- Hunk stage/undo/preview no longer saves the buffer.
- Hunk undo no longer makes locations go out of sync.
- Grep can be opted out of (grep output with ansi escapes is number one cause
of issues).
- Replaced g:gitgutter_grep_command with g:gitgutter_grep.
- Always runs git-diff the same way instead of in two possible ways.
- Separated detection of git tracking from diffing.
- Simplified path handling.
- Removed support for xolox shell: Windows taskbar does not flash with async
jobs.
- Removed g:gitgutter_{eager,realtime}.
- Simplified implementation generally.
Also don't pass buffer number to functions when they can look it up
themselves.
Using buffer numbers also eliminates any ambiguity which might arise
from symbolic links, where you have potentially two names for a file.
Thanks to @Z1MM32M4N for work on this (see #209).
