Squashed '.vim/bundle/vim-fugitive/' changes from 8f0b8ed..17393f5

17393f5 Don't blow up on type checking empty buffers
51cdb1b Cater for powershell as well as cmd for windows users
c1664de Don't blow up on vanishing HEAD
d6540b2 Work around issue using buffer number rather than name
22cc877 Add missing aborts
218fc37 Revert "Work around more 'wildignore' silliness"
3bfa0a2 Work around more 'wildignore' silliness
fd297ad Set winfixwidth
a069fa7 Accidental omission from previous commit
d6f1760 Support :Gcommit --patch
70ec927 Improve keepjumps situation
b27937d Turn off swap files in all URL buffers
152c919 Check `&diff` first in fugitive_diff autocmds
7c40a18 Fix version regex
f395f3c Improve heuristics for status section detection
0765cbe Place extra emphasis on a clean history
0cb3054 Look for $GIT_DIR and $GIT_WORK_TREE
190fe2a Store more than just dir in s:temp_files

git-subtree-dir: .vim/bundle/vim-fugitive
git-subtree-split: 17393f552e3a51dd010f403073592bf0a6170098
Merge commit '2dc3a1ef84774af75046ec2441625c8e0e0e0983' into personal