Escape the optgroup labels during initialization step.
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 branch 'xss_fixes_from_defectify_com' of github.com:zsombor/chosen into better_text_escaping

Conflicts:
	chosen/chosen.jquery.js
	chosen/chosen.jquery.min.js
	chosen/chosen.proto.js
	chosen/chosen.proto.min.js
	coffee/lib/abstract-chosen.coffee
Move escapeExpression into SelectParser
Merge branch 'master' into better_text_escaping
Merge branch 'master' into option-group-sarch
Merge branch 'option-group-sarch' into better_text_escaping
Merge branch 'master' into option-group-sarch
Always make sure an option's search_text gets reset when winnowing.

This fixes an issue where group search text doesn't get reset
properly and simplifies the match functionality.
Merge pull request #1343 from harvesthq/option-group-sarch

Search Optgroups