Squashed '.vim/bundle/vim-fugitive/' changes from 17393f5..e7c7149

e7c7149 Map both g? and <F1> to show help
c8070ae Ridiculous hack to set cursor position on :Gdiff
21b60b3 Support implicit github username in remote
9649b02 Fix modeline errors in historical buffers
cbab574 Make commands available in command line window
72d3820 Revert "Work around issue using buffer number rather than name"

git-subtree-dir: .vim/bundle/vim-fugitive
git-subtree-split: e7c7149434e819ed385bec004a45a222f74e3f1f
Merge commit '8226de54fa2cd6cc7e51d12a622cdd9ab03f2a44' into personal