Stub DOM event handlers for filter form elements
Implement faceting of Providers collection
Don't use grunt-newer in default grunt task
Remove empty items from multivalue fields

When parsing spreadsheet values and converting multivalue fields
into lists, remove the empty strings.  This is needed because

``"".split(/;\s*/);``

returns ``[""]``.
First pass at filtering list

Add a view that filters the list, trigger some events that can be
used to kick off the filtering.
Handle filtering in case where attribute is single value
Make filters work together
Use correct attribute names
Ignore blank values in Providers.facetOptions()
Merge branch 'master' into gh-pages
Rebuild.