fix whitespace indent setting changed incorrectly when toggling
fix warning separator colors out of sync between modes
extract matching background colors for file indicator
fixes error when colorscheme declared in gvimrc. resolves #126.
allow extensions to reload when color scheme changes. resolves #128
add ability to override left/right sides independently
Merge branch '127'

Resolves #127.

Conflicts:
	autoload/airline.vim
enable tagbar only for active windows
use hack fix for now. resolves #105.
extract iminsert out of core into an extension
update documentation
make the mode and branch text window local
introduce g:airline_inactive_collapse. resolves #129.
remove checks for airline_active, it is always true
improve bufferline integration; revert to default in inactive splits.
remove support for inactive modified

statuslines don't actually get evaluated in inactive splits, so this feature never worked properly anyways.