FIX 673 Prevent double execution of onmatch on cms-add-form FIX Properly...

... selct the right item when choosing pagetype during new page creation

I'm not too proud to have to set a flag after the onmatch is performed, but onmatch is called a second time after the first click on one of the radio of the pagetype, and there's no known fix for that (see https://groups.google.com/forum/?fromgroups=#!topic/jquery-entwine/Y0mDxM_kHbQ)