Avoiding deprecated calls to Run.getEnvironment(); need to pass in a TaskListener.

Conflicts:
	src/main/java/hudson/plugins/git/GitSCM.java
[maven-release-plugin] prepare release git-2.2.6
[maven-release-plugin] prepare for next development iteration
[FIXED JENKINS-21464] save current Build in BuildData before re-scheduling job
Avoid NPE in GitPublisher when slave is disconnected

Null pointer exception was reported in jenkins log file after the node
which hosted the preceding build was disconnected.
Checkout a known tag from the repo so test job doesn't fail prematurely
[FIXED JENKINS-20427] [FIXED JENKINS-14276] expanded vars in branch spec for remote polling
use pollEnvironment during … polling
Temporarily remove NPE test - fails in Jenkins, works from cmdline and IDE
Add a `GIT_PREVIOUS_SUCCESSFUL_COMMIT` environment variable
Test the environment variables