Add winnow results to results_update_field

This allows triggering the listz:udated event to also refresh
out of date search filters
Escape the optgroup labels during initialization step.
Add some keywords for the jQuery plugin repository.
added compass for sass compilation
use border-radius, box-shadow, text-overflow, background-clip without prefix
removed IE filter
short color codes
nesting of selectors
class variants using parent references (&)
removed unused chzn-results-scroll* classes
IE9 without gradients
sort properties using csscomb
Make use of image-url helper
Updated gruntfile and compass config
Add GitHub urls for our contributors.
Ruidmentary group searching in place.
Mark search results that don't match as found if their parent group is
also found.
Move the search string tester into its own method.
When an option matches, mark its parent group as matched as well.
Change the name of the group search option.
Groups that have search matches should also get highlights!
Merge pull request #1320 from koenpunt/css-to-sass

Use SASS for CSS generation.
Make sure Chosen Zip gets version number.