status: fix handling of filenames with special prefixes

Fix libgit2/libgit2sharp#379
Added ssh transport file
Renaming
Adding ssh transport logic
Push working over ssh
Cleanup
Added ssh stream cleanup
Refactoring
Added support for ssh:// urls
Added username and password auth for ssh
Cleanup
Refactoring
Renaming
Cleanup
Added SSH public key authentication
Fixed compilation issues when libssh2 is missing
Added libssh2 cmake module
Merge remote-tracking branch 'origin/development' into ssh_transport
Added ifdef
Introduce git_reference_shorthand

Generate a shorthand name out of the full refname.