implementing solr faceting for categories
improved facets implementation and added ajsp file for manageCategories
filtering working for each category that was clear for me from concept class seperately and has no counts so-far
removed FacetForACategoryFilter and rether implemented faceting by another way, added all available concept classes in the 1.9.0 demo database as category filters, all available filters are now working well, refactored code
Merge pull request #15 from k-joseph/CSM-58

[CSM-58] Define categories