This removes the g:gitgutter_sign_column_always option.
Vim 7.4.2201 introduced the |signcolumn| option to configure when the
signcolumn is visible, building in behaviour which the plugin provided
manually.
Although it would be good to maintain this feature for older Vims, the
complexity added by the code outweighs the benefit of backward
compatibility.
In fe2b4ec869 (from 2013) the plugin
started using a dummy sign to prevent the sign column briefly
disappearing then reappearing when updating signs.
Since then Vim has vastly improved its handling of signs and the sign
column no longer flickers like this.
- 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).
