Force SASS syntax for .scss files
Add F5 to toggle between relative and regular line numbers. Default to relative for now.

http://jeffkreeftmeijer.com/2012/relative-line-numbers-in-vim-for-super-fast-movement/
Merge branch 'master' of github.com:pgib/pgib-vim-config
Disable relative line numbers in insert mode and when vim loses focus.
Add note about F5