Entity, Installer, UI and Misc fixes.

This is my progress on Dizkus until now.
I need it runing decently enough for production and I saw it's already pretty advanced to get it there. Thanks a lot! :)

So, I've reviewed the stuff and adjusted the Doctrine 2 entities relations to make then work in a clean install, and from here I need some help to adjust the consequences, like the Forum creation, which got broken by the declaration of the relations I guess, have to review what's the Doctrine requirements now to Create/Edit records.

I considered unnecesary to sepparate the misc fixes commits from the Entity/Installer ones, so here they are all in this PR. I need some help to check the issues of the Entities forms handling.
TIA