Introduced the use_dash_c argument.
When true (the default), we will call git with the -C argument, but that requires git 1.8.5 or higher.
When that requirement cannot be met, one can pass false, which will fall back to the --git-dir and --work-tree arguments. Because we need to traverse the current working directory up to root and search for a .git directory, this options is less performant and accurate. Therefor using git 1.8.5 or higher is recommended.
This release should solve the working directory issues (#1 and #4) once and for all!