Also makes it so that, if every size is marked 'all forms',
changing forms doesn't reset to the form's default size.
This makes sense for characters whose forms are all the same
size.
Also lets models have a default view for each form. Fixes some incorrect
behaviors with the setup of entities to go along with this (e.g. if there
was no default form, the last form would wind up being the default, rather
than the first, if default views were specified.