* GET /repos/:owner/:repo/commits/:ref

* add Validation Checks

* Fix & Extend TEST

* add two new tast cases

* Fix validate() function to handle errors in embedded anon structs

* Implement webhook branch filter

See #2025, #3998.

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

If you add t.Logf("%+v %+v", actual, testCase.expectedErrors) to
the test code, you'll notice that only Errors' Messages are being
compared:

    --- PASS: Test_ValidURLValidation/Invalid_schema (0.00s)
    binding_test.go:43: [Url] [Url]

FieldNames and Classification are ignored in comparison.

Moreover, an Errors slice with a single Error with empty message
is formatted as '[]' (the same as empty slice), which is also
error-prone. I discovered this when working on #7791 when one test which
was not supposed to pass did pass. https://play.golang.org/p/qC4wVLrm4NG

This commit changes the test to do the comparison properly.

* Validate External Tracker URL Format

Add some validation checks for external tracker URL format.

Fixes #7068

* Don't make {index} a hard requirement

* Fix Description

* make fmt

* move regex to package level

* fix copyright date

* Clean up ref name rules

Clean up checks on reference names to better conform to the guideline
here: https://git-scm.com/docs/git-check-ref-format

This fixes half of #6321

* Update branch create integration test

According to: https://git-scm.com/docs/git-check-ref-format

And: git check-ref-format "master/feature=test1"

This is a valid branch name and we should not be testing for it to fail.

* Improve URL validation for external wiki  and external issues

* Do not allow also localhost address for external URLs

* Create new branch from branch selection dropdown and rewrite it to VueJS

* Make updateLocalCopyToCommit as not exported

* Move branch name validation to model

* Fix possible race condition

* Add correct git branch name validation

* Change git refname validation error constant name

* Implement URL validation based on GoLang url.Parse method

* Backward compatibility with older Go compiler

* Add git reference name validation unit tests

* Remove unused variable in unit test

* Implement URL validation based on GoLang url.Parse method

* Backward compatibility with older Go compiler

* Add url validation unit tests