Revamed DB constraints triggers
Revamed DB constraints triggers

 * Created new trigger for delete operations where we basically only
   check if the to-be-deleted prefix is of type assignment and if so, we
   block the delete if there are any prefixes inside the assignment
   prefix.
 * Block the changing of type for a prefix.

bbaja42/NIPAP,SpriteLink/NIPAP,plajjan/NIPAP,bbaja42/NIPAP,garberg/NIPAP,plajjan/NIPAP,garberg/NIPAP,plajjan/NIPAP,ettrig/NIPAP,SpriteLink/NIPAP,bbaja42/NIPAP,plajjan/NIPAP,fredsod/NIPAP,garberg/NIPAP,ettrig/NIPAP,ettrig/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,ettrig/NIPAP,fredsod/NIPAP,bbaja42/NIPAP,plajjan/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,plajjan/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,garberg/NIPAP,fredsod/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,ettrig/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,garberg/NIPAP