Calculate game's initial character level on hard reload
Add d&d game type to seed

This is done, because the xp algorithm is extremely complicated, and it
could serve as an example of how to do something complicated in that
field.
Require levels present when leveling up

In order to level up a charcater, there should be available levels. This
patch ensures that if there's no levels, the user will be redirected
back to his characters.
Evaluate xp algorithm correctly when calculating start level
Make game system appear as required in forms