Make versioning work regardless of the root.

Also make some things more groovy-y.

Change-Id: Iced4396b6a43f2548f0633f982edc63e7b978770
Reviewed-on: http://gerrit.dmdirc.com/4029
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager