Added Mercurial (HG) support

[clarenceb]

Thanks for creating this plugin. Its very useful. Where I am currently working we use Mercurial repositories and I saw your plugin doesn't support it yet. I made some changes to it and it now works with Mercurial. Feel free to accept the changes if you are happy with them.

Things to note:

• I couldn't figure out how to initialise a HG repo like "git init --bare" . It seems I had to commit a file for the repo to be valid for the tests (hg locate would fail otherwise). Let me know if you know a better way!
• Due to the behaviour above, in a couple of tests I have to specifically check if we are testing against a HG repository and then remove the special dummy file so the tests can pass.

[buildhive]

Jenkins » scm-sync-configuration-plugin #26 SUCCESS
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[fcamblor]

Sounds great ! :-)

Will take a little time during christmas to review this. Thanks.

[LionelOnTech]

Fantastic! Always needed this to work with Mercurial as well. Thanks! Hope it gets incorporated soon.

[dbatwa]

This is very useful. When is it getting pulled?

[fcamblor]

An issue already exists and is blocked by a wider problematic

I know this is not hard to click the "merge pull request" button, but we must think about long term support

[jenkinsadmin]

Thank you for a pull request! Please check this document for how the Jenkins project handles pull requests

[danehammer]

Given this has been sitting here for 2 years, I don't agree with the notion that a very good idea for refactoring can block this being pulled in, because for the last 2 years this work has been left sitting here.

I would be willing to get this back up to snuff with master, but is it going to remain blocked by JENKINS-18124?