It didn't really make sense showing the libgit2 version number in the synopsis. It seems like it is better suited to the description field so that you only see it when you look at the hlibgit2 page directly. I also changed 'Generated bindings' to 'Low-level bindings' in accordance with many of the other bindings on Hackage. Perhaps we should rename the library to bindings-libgit2? This seems to be a common naming scheme for bindings on Hackage.
The libgit2 version is determined using `git describe`
This is no longer required as the cabal/ghc builds libgit2. I didn't remove it all together as it is useful to uncomment and use as a sanity check. It is also the only was to run the libgit2 tests.