Blog: when getting entity manager of first blog, return default entity manager
Revert "Blog: when getting entity manager of first blog, return default entity manager"

This reverts commit d33a2af3ebea52fbc61edfd9c5242b0e7e9487c0.
Entity: remove nongeneric validation groups
Merge pull request #13 from luiges90/master

Entity: remove non-generic validation groups