Styling disabled filter elements

When a filter element is disabled this state should be reflect through its style. Since the css classes are already there I've simply added a different background color. You can, of course, hide them by adding `display:block;` instead.
Merge pull request #283 from riker09/patch-1

Styling disabled filter elements
Bootstrap disabled filters styling update
added filter_filteredRow class name option; used by the pager
triggered filter searches now update the inputs properly; see #146
filter_searchDelay no longer ignored (broken in v2.9.0)
filter_liveSearch now works properly in non-webkit browsers; fixes #285
filter_liveSearch can now contain a minimum number of characters; see #286
Fixed content selection & form interaction in the headers/sticky headers; fixes #57
filter-select updates properly within the sticky header; fixes #288
added stickyHeader_offset; fixes #294
added stickyHeaders_addResizeEvent option with public function; fixes #289
fixed a stickyHeaders_offset issue
started caching pager controls
pagerComplete callback now fires once per change; fixes #291
ajaxProcessing return optional jQuery object; updated error handling & theme css
Pager + filter now shows 0 matches properly; fixes #297
updated digit & currency parsers, added missing sortBegin - found via unit testing
filter widget now works properly with date comparisons; fixes #302
Added ajaxObject option; fixes #280