Adjust JIRA component.

According to https://wiki.jenkins-ci.org/display/JENKINS/2014+JIRA+Components+Refactoring
Merge pull request #272 from KostyaSha/upd

Adjust JIRA component.
Implement ancestry build chooser
Improve test coverage slightly
Make AncestryBuildChooser fields immutable
Update package name of AncestryChooser groovy config file
Fixed JUnit tests for JENKINS-24133 on Windows
[FIXED JENKINS-20427] [FIXED JENKINS-14276] expanded vars in branch spec for remote polling
Update git-client-plugin to 1.12.0 [JENKINS-25639]

Need the Revision.equals() implementation to fix JENKINS-25639
Update mockito to 1.10.13
DefaultBuildChooser.getCandidateRevisions() now returns Set<Revision> to filter duplicates.
[FIXED JENKINS-25639]
test DefaultBuildChooser with unknown SHA1
[FIXED JENKINS-23675] Expand parameters on repository url before associate one url to one credential
Remove JGit and Guice repos from pom

Get that content from other dependencies
[maven-release-plugin] prepare release git-2.3.1
[maven-release-plugin] prepare for next development iteration