Adding Git information to the assembly target jars.

unzip -p <file>-server.jar META-INF/MANIFEST.MF | grep ^Git
Git-Repo-Is-Clean: false
Git-Branch: git-sbt
Git-Build-Date: 2014-11-17T23:08:19.665-08:00
Git-Head-Rev: 257fd0368dda294db1d54e7ae8c6560be4ef1019
Let's move this up just after assemblySettings.

Also, the spark connector makes an assembly jar that could benefit from having the Git Stamp. The gitStampSettings will also need to be added after assemblySettings in the spark project below.