Merge pull request #122 from MarkEWaite/master

Improve isRevExcluded performance by avoiding call to "git show" if no exclusions are defined
FIXED - JENKINS-16453
added null check
finally returning flag value instead of false
removed exception handling
added a basic test
add email address properly if already known
Merge pull request #123 from richtmat/master

Fixing JENKINS-16453
Set java source/target to 1.6 for maven
Set compiler source/target to 1.5 for Maven
remove FilePath from GitAPI, just local File
GitARPI don't have to know about remoting, 
just handle git specific stuff (separation of concerns)
Update the Git logo icons
Merge pull request #127 from tombevers/update-git-logo

Update the Git logo icons