fix for NPE on CDR fesl cache invalidation
In the hierarchical browse view, hidden folders with visible contents now display the contents as if the folder were not there, which fixxes cdr-129.  The base 'browse' header link now correctly goes to the collection browse page again.  SolrUpdateServiceTest actually making assertions now.
Removed extraneous sorting of facet categories, leaving it to the order of the facet fields in the request to set order.  All the maps and sets in SearchSettings declared as generic interfaces.
Display collection placeholder image instead of the fake thumbnails from the static folder now.  Browse link from container full record page correctly going to just the first tier of results again.  Turned logging back down to warn.
Fedora content streaming prioritizing fedora headers for content length and mimetype over those from solr when present and valid to avoid getting incorrect data back when requesting datastreams before the object they belong to has been updated in Solr.  Cleaned up some system.out statements
Preventing an out of bounds exception from occurring when only 1 column is found for an entry in the list of worked files when populating the ingest monitor.  Turned down solr ingest logging for services
Using the display department field for facet lists
Fixed about page links to use the scontent path instead of external