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)

Chrono clone fix

Fix nil index error in makeParadoxClone

I'm not sure how/why it happened, but while testing the 1.3.2 beta cut
I got a nil index error in makeParadoxClone() while try to index on
getInven("INVEN"). My character did have an inventory, so this seems
strange. Anyway, it makes sense to check whether INVEN exists before
trying to skip it.

Now, the function checks whether INVEN exists before adding it to the
alt_nodes table.

This should be pushed to 1.3.2.

It's probably safer not to change this, on the off chance that we
actually spawn a clone of a dead actor.