Merge branch 'development'
Add helpful buffer shorten function
Make refspec_transform paranoid about arguments
Merge pull request #1692 from arrbee/fix-1692

Segmentation fault on git_clone
Make the git_signature const in the stash API.
Merge pull request #1715 from tiennou/const-signature

Make the git_signature `const` in the stash API.
Merge remote-tracking branch 'upstream/development' into development