DDF-894 - Added "no-value" facets to all calculated facets

-added abilty to facet on "No Value" fields.  There are , however, some
hard-coding of metadata-content-type going on but for the most part its
generic.
-added grunt "dev" task to help speed up my starting and stoping of my
server without having to do a full bower install.  Saves devs alot of
time.
-added sorting to the metadata-content-type facet list.  No value should
be on the bottom and the rest are sorted by name.
That was my initial thought as well, but since the property is not required it may not even exist to have a null value. Not sure if we need to distinguish between exists and null though.