Correctly handle simultaneous assignee/poster filters, and conflicting assignee filters

a transaction session was in progress. MailParticipants was failing
silently because of the SQLITE_LOCKED error. Make sure failures in
MailParticipants enter the log, and pass on the transaction context.

issue: let caller pass in database context, and use it
issue_comment: obtain database context to pass to UpdateIssueMentions
issue_comment: log any error from call to MailParticipants
issue_mail: pass on database context to UpdateIssueMentions

Also address other TODOs

Also move duplicated code into repo.APIFormat(..)

From code.gitea.io/go-sdk/gitea
  To code.gitea.io/sdk/gitea

- 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

See https://github.com/golang/go/wiki/CodeReviewComments#mixed-caps

* Fix PR-webhook issue where Label-data is stale

* Conventions \o/

* logs are nice if they're consistent...

- Fill Milestone and Assignee field when available in webhook payload

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

Unix() already uses UTC as timezone