Implemented "shell" command for windows and using git subcommands
Implemented "shell" command for windows and using git subcommands

Using 'git upload-pack' instead of 'git-upload-pack', same for
'git receive-pack'. Reason is msysgit on Windows which has all
subcommands directly compiled in the 'git' executable.

NiklasRosenstein/git-auth,NiklasRosenstein/git-auth