vim-gitgutter is buggy. vim-signify might be better, it does allow
configuration of which events trigger a sign column update and this
patch takes advantage of that. Firstly, the `CursorHold` and
`CursorHoldI` events are disabled and replaced with `InsertLeave` and
`TextChanged` events. This makes the sign column updates immediate, and
since vim-signify is asynchronous it's faster too.
vim-sensible includes and old matchit.vim which interfears with
vim-matchup and sets some defaults which are then overridden in
plugins/settings.vim. Remove vim-sensible and document the retained
settings.
