Item12742:Item12743: protect against infinite recursion on mal-formed category data

also:
- added quality checks for tagging, categorization and use of headings
- added sort parameter to %HIERARCHY macro
- added EXCLUDE parameter to RenderCategory TopicFunction
- deprecated use of old new-category form
- improved template WebHome for classification webs





git-svn-id: http://svn.foswiki.org/trunk/ClassificationPlugin@17271 0b4bb1d4-4e5a-0410-9cc4-b2b747904278