This PR fixes #7598 by providing a configurable way of signing commits across the Gitea instance. Per repository configurability and import/generation of trusted secure keys is not provided by this PR - from a security PoV that's probably impossible to do properly. Similarly web-signing, that is asking the user to sign something, is not implemented - this could be done at a later stage however.

## Features
- [x] If commit.gpgsign is set in .gitconfig sign commits and files created through repofiles. (merges should already have been signed.)
- [x] Verify commits signed with the default gpg as valid
- [x] Signer, Committer and Author can all be different
    - [x] Allow signer to be arbitrarily different - We still require the key to have an activated email on Gitea. A more complete implementation would be to use a keyserver and mark external-or-unactivated with an "unknown" trust level icon.
- [x] Add a signing-key.gpg endpoint to get the default gpg pub key if available
    - Rather than add a fake web-flow user I've added this as an endpoint on /api/v1/signing-key.gpg
    - [x] Try to match the default key with a user on gitea - this is done at verification time
- [x] Make things configurable?
    - app.ini configuration done
    - [x] when checking commits are signed need to check if they're actually verifiable too
- [x] Add documentation

I have decided that adjusting the docker to create a default gpg key is not the correct thing to do and therefore have not implemented this.

Signed-off-by: Tamal Saha <tamal@appscode.com>

* fix bug create/edit wiki pages when code master branch protected

* improve FullPushingEnvironment function

* Add options to git.Clone to make it more capable

* Begin the process of removing the local copy and tidy up

* Remove Wiki LocalCopy Checkouts

* Remove the last LocalRepo helpers

* Remove WithTemporaryFile

* Enable push-hooks for these routes

* Ensure tests cope with hooks

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove Repository.LocalCopyPath()

* Move temporary repo to use the standard temporary path

* Fix the tests

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove LocalWikiPath

* Fix missing remove

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Use AppURL for Oauth user link (#6894)

* Use AppURL for Oauth user link

Fix #6843

* Update oauth.go

* Update oauth.go

* internal/ssh: ignore env command totally (#6825)

* ssh: ignore env command totally

* Remove commented code 

Needed fix described in issue #6889

* Escape the commit message on issues update and title in telegram hook (#6901)

* update sdk to latest (#6903)

* improve description of branch protection (fix #6886) (#6906)

The branch protection description text were not quite accurate.

* Fix logging documentation (#6904)

* ENABLE_MACARON_REDIRECT should be REDIRECT_MACARON_LOG

* Allow DISABLE_ROUTER_LOG to be set in the [log] section

* [skip ci] Updated translations via Crowdin

* Move sdk structs to modules/structs (#6905)

* move sdk structs to moduels/structs

* fix tests

* fix fmt

* fix swagger

* fix vendor

* move code.gitea.io/git to code.gitea.io/gitea/modules/git

* fix imports

* fix fmt

* fix misspell

* remove wrong tests data

* fix unit tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* enable Debug to trace the failure tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* comment commit count tests since git clone depth is 50

* fix tests

* update from code.gitea.io/git

* revert change to makefile

* Fix serving of raw wiki files other than .md

Closes #4690.
Closes #4395.

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Simplify code at routers/repo/wiki.go

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Add more files to user2/repo1.wiki for testing

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Update macaron to v1.3.2

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Add tests for WikiRaw

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Fix NewResponseWriter usage due to macaron update

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* Add raw to reserved wiki names

Signed-off-by: Gabriel Silva Simões <simoes.sgabriel@gmail.com>

* fix deadlock when sqlite

* fix clonelink deadlock on sqlite

* Fix rendering of wiki page list if wiki repo contains other files

* Improve wiki filename tests

* Remove hardcoded paths to fix randomly failing tests

* Use correct function for merge path

* Update macaron

* Various wiki bug fixes

* Update code.gitea.io/git

* Update function calls

* govendor fetch

* git: delegate all server-side Git hooks (#1623)

* create hooks directories

* take control hooks back

* fix lint

* bug fixed and minor changes

* fix imports style

* fix migration scripts

This change corrects a few logging issues:

 * Standardized formatting errors with '%v'.
 * Standardized failure warning word usage.
 * Corrected an instance of using the standard log library when
   the gitea log library should be used instead.

Suppress the error when we're removing a file that may not exist

See #70

- Update import paths from github.com/go-gitea to code.gitea.io
- Fix import path for travis

See https://docs.travis-ci.com/user/languages/go#Go-Import-Path

* Replace gogits/git-module dependency with go-gitea/git

Fixes #92

* Remove git alias for git module import (not needed)

commit 0afcb843d7
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 17:13:29 2016 -0600

    Removed Upload stats as the upload table is just a temporary table

commit 7ecd73ff55
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 08:42:41 2016 -0600

    Fix for CodeMirror mode

commit c29b9ab531
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 08:03:33 2016 -0600

    Made tabbing in editor use spaces

commit 23af384c53
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 07:56:46 2016 -0600

    Fix for data-url

commit cfb8a97591
Merge: 7fc8a89 991ce42
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 07:42:53 2016 -0600

    Merge remote-tracking branch 'gogits/develop' into feature-create-and-edit-repo-file

    Conflicts:
    	modules/bindata/bindata.go
    	public/js/gogs.js

commit 7fc8a89cb4
Merge: fd3d86c c03d040
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 07:40:00 2016 -0600

    Merge branch 'feature-create-and-edit-repo-file' of github.com:richmahn/gogs into feature-create-and-edit-repo-file

commit fd3d86ca6b
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Sun Jul 31 07:39:44 2016 -0600

    Code cleanup

commit c03d0401c1
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Fri Jul 29 15:38:23 2016 -0600

    Code cleanup

commit 98e1206ccf
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Thu Jul 28 18:36:01 2016 -0600

    Code cleanup and fixes

commit c2895dc742
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Thu Jul 28 18:24:04 2016 -0600

    Fixes per Unknwon's requests

commit 6aa7e46b21
Merge: 889e9fa ad7ea88
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Thu Jul 28 17:13:43 2016 -0600

    Merge remote-tracking branch 'gogits/develop' into feature-create-and-edit-repo-file

    Conflicts:
    	modules/bindata/bindata.go
    	modules/setting/setting.go

commit 889e9faf1b
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Fri Jul 22 14:09:18 2016 -0600

    Fix in gogs.js

commit 47603edf22
Merge: bb57912 cf85e9e
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Fri Jul 22 14:07:36 2016 -0600

    Merge remote-tracking branch 'gogits/develop' into feature-create-and-edit-repo-file

    Conflicts:
    	modules/bindata/bindata.go
    	public/js/gogs.js

commit bb57912558
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Fri Jul 22 14:02:18 2016 -0600

    Update for using CodeMirror mode addon

commit d10d128c51
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Tue Jul 19 16:12:57 2016 -0600

    Update for Edit

commit 34a3498202
Merge: fa1b752 1c7dcdd
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Tue Jul 19 11:52:02 2016 -0600

    Merge remote-tracking branch 'gogits/develop' into feature-create-and-edit-repo-file

    Conflicts:
    	modules/bindata/bindata.go

commit fa1b752be2
Author: Richard Mahn <richard_mahn@wycliffeassociates.org>
Date:   Fri Jul 15 18:35:42 2016 -0600

    Feature for editing, creating, uploading and deleting files

- Arbitrary file creation leading to command execution
- .md file creation/deletion

Reported by Gabriel Campana.

(untested)