Fixed the game not starting on some latest ubuntu installs

Actor fov doc fix

The fact that I had to engine-dive to know what exactly no_store parameter in ActorFOV does inspired me to improve the documentation note on it.

The bad thing is, having it set to true breaks a lot of functions which depend on actor.fov.actors

If desired, I could improve the @ notes on other functions, too.

undead horrors can summon even without the undead files loaded

undeads cant use infusions instead of only being able to use runes (doesnt change anything for vanilla)

If a module or addon errors out on the loading screen it will jump into a "safe mode" to display the error message and then go back to the main menu

Buffed curse of nighmare to start triggering at level 4 (as the description was implying)