fixed bug in getRelatedTags(), changed findOrCreateByTagname() so that it is not static anymore
fixed bug in getRelatedTags(), changed findOrCreateByTagname() so that it is not static anymore

git-svn-id: 14431f16c86e063b591b7186ad64c5043b5760e0@30975 ee427ae8-e902-0410-961c-c3ed070cd9f9

Virtuvia/sfDoctrineActAsTaggablePlugin,Virtuvia/sfDoctrineActAsTaggablePlugin