libgit2/libgit2sharp — pull request #290 by Saaman (2013-01-07 21:25:48+00:00)
Title: adds ReferenceAlreadyExistsException and wrap native exception in it

I followed the idea proposed [here](https://github.com/libgit2/libgit2sharp/issues/267#issuecomment-11127883) and adds a new `InputAlreadyExistsException` class to wrap `EEXIST` native exception from libgit2.

Hope it helps!