qnd: merge r90313 from trunk to support external entry plugin
r90313:
Support using partner class wrapper. 
Throw exception when wrapper class not found.

git-svn-id: svn+ssh://kelev.kaltura.com/usr/local/kalsource/backend/server/tags/falcon_2012_08_20@94036 6b8eccd3-e8c5-4e7d-8186-e12b5326b719
adding empty directories