Unclassified counts

* show unclassified failure counts for all watched branchs
* toggle button to show unclassified failure count on current branch, and toggle to show only unclassified failures
* refactored ``jobfilters.js`` somewhat to take function definitions out of the ``api`` block, like we do with other classes
* add new methods to ``jobfilters.js``:
    * ``isUnclassifiedFailures`` checks if we are currently filtered to show only unclassified failurs
    * ``showUnclassifiedFailures`` set filters to show only unclassified failures
    * ``resetNonFieldFilters`` reset all the checkbox filters to their default state.  Used to undo ``showUnclassifiedFailures``
* removed pinned jobs count