[FIX] Cleanup and set empty value in event of no value jsut in case


git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@53294 b456876b-0849-0410-b77d-98878d47e9d5
[ENH] Allow finding out which addon is used from the page being viewed (if current page is created by an addon) and setting {{cat}} automaticaly if {{organicgroup}} is set.


git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@53295 b456876b-0849-0410-b77d-98878d47e9d5