implemented a append and strip possibility for the Trac Browsing URL
Updated help texts
Finished [JENKINS-13366] for Trac git repositories.
The implementation and tests for Trac subversion repositories is
pending.
[FIXED JENKINS-7032] and [FIXED JENKINS-13366]
Implemented and tested the strip and
append feature of the URL parts before the final Trac URL is build.
Merge pull request #5 from GerdZanker/JENKINS-7032

Fix for JENKINS-7032 and JENKINS-13366