jshint fixes
Adding category_facet dropdown
Updating tests
IE fixes, fixing tests components tests
Merge branch 'editor-fixes' into devel-dataset-compare
Adding dataset checkbox on edit form

* fixing some jshint warnings
* removing commented code
* adding new *multiple_datasets* property on model
* removing code that added "(X)"/"(Y)" to facet labels
* adding dataset facets when *multiple_datasets* is *true*
* moving *constraints* and *position* code to separate functions
* setting no constraints for *all-values* facets