Speed up git version retrieval by using jgit-describe.jar (Built from https://github.com/ShaneMcC/jgit-describe) to describe the git tag rather than shelling out.
This stops plugin jar building taking 2-5 seconds per plugin by shelling out.
Whilst not a fix exactly for CLIENT-330 - it will make it less of a pressing concern. It would still be nice to fix it though.
Change-Id: I23030c6e060ab651e5ecd4aab6d671aa762ac8ac
Reviewed-on: http://gerrit.dmdirc.com/2267
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>