[FIXED JENKINS-20561] fix migration of skipTag property for job using configuration format version 1
Merge pull request #179 from ydubreuil/fix-JENKINS-20561

[FIXED JENKINS-20561] fix migration of skipTag property for job using configuration format version 1
If !skipTag, PerBuildTag is added, so test with it true.
Working towards making it possible to test this plugin against newer Jenkins cores using plugin-compat-tester.
Delete sample changelog at end of test - check for open file leak

JENKINS-20585 reports that changelog.xml cannot be deleted on Windows
because it is held busy by a process.  This test assumes that process
is Jenkins itself, and that the GitChangeLogParser.parse() method is
the most likely culprit.
Changed to allow creating RevisionParameterAction using existing Revision, from a previous build for example. This provides the sha1, branches, etc. as they exist in the Revision for the parameter action on the new build.
Merge pull request #182 from daldinger/RevParms

Changed to allow creating a RevisionParameterAction using an existing Revision
[FIXED JENKINS-17417] Expand Branch Specifier

Expand Branch Specifier with build environment variables.

Note that the Branch Specifier is not expanded for repository polling
because no build environment is available at that time.
Merge remote-tracking branch 'upstream/master'
[JENKINS-20502] enforce configured refspecs have been fetched
clone don't handle custom refspecs, so need to run fetch
[JENKINS-20318] use git-credentials-store
Merge remote-tracking branch 'upstream/master'
set remote.<name>.url
now that git-client 1.5.x stop exposing credentials in .git/config 
(thanks to git-credentials) we can set remote.<name>.url
this fix broken GitPublisher
Merge remote-tracking branch 'upstream/master'
Update git-client dependency now that 1.6.0 has been released
Merge pull request #184 from MarkEWaite/master-pom-update-jgit-client-1.6.1-SNAPSHOT

Update jgit-client version in pom to git-client 1.6.1-SNAPSHOT
[JENKINS-19994] Close files opened by computeChangeLog, use new abort() method

All calls to a changelog instance must conclude with either a call to
execute() or a call to abort().  Files will be left open if one of
those two methods is not called before the changelog instance goes out
of scope.
Merge pull request #185 from MarkEWaite/JENKINS-19994-close-changelog-opened-files

[JENKINS-19994] Close files opened by computeChangeLog, use abort()
Create MIT-LICENSE.txt
[maven-release-plugin] prepare release git-2.0.1