Loosen regex to compensate for iskeyword

Closes #332.
Add foldenable to fugitive_diff_restore
Revert "Add foldenable to fugitive_diff_restore"

This reverts commit cbb7c3e89026472dfbc5440d78ce85975423bedd.
Encapsulate restore options for diff

This should make it easier to experiment with solutions for issues such
as #257.
Press - on first line of :Gstatus to edit .git

This is a bit silly, but provides a quick way to start navigating the
repository.  Press it a second time and you're in the work tree root.
Change heading style
Extract contribution guidelines
Update :Gblame explanation in README
Fix :Gstatus dp with external diff enabled

Closes #341.
Support angle quotes in git status

Closes #228.
Fix :Gmove command on Windows
Change if block to correct ending
Fix write to index with msysgit bash

Closes #388.
Don't set global foldlevel

Without this change, Fugitive will routinely overwrite the global foldlevel. It shouldn't.
Fix unmatched parens in :Gmove
Add ability to query current Git version
Work around new status style in 1.8.5

Closes #393.
Fix slowness when searching for networked git repos under Cygwin.

The algorithm in fugitive#extract_git_dir() is to move upwards in the
file system hierarchy until a sub-directory called .git is found. When
accessing a file on a network share from a Cygwin Vim and the file is not
within a git repo, this eventually causes a check for the existence of
//serverName/.git and //.git. Such checks are extremely slow so let's
avoid them.
Add & modify autocmd events `FugitiveBoot` & `Fugitive`

- Change old `Fugitive` to `FugitiveBoot`

- Put `Fugitive` at the end of fugitive#detect
Reopen diff folds when diff ends

References #36.