The handling for the two frozen flags was totally inconsistent.
Furthermore, these need to be session data, not level data.
The old exported variables for this still exist and shadow the real state, but are deprecated now.
Frozen state should only be checked with "currentSession.isFrozen()" now.
The session data in the savegame was grouped and separated from the global state, which onl consists of server CVARs and RNG state now.
Unlike the other classes, the places where variables from this class were accessed were quite scattered so there isn't much scriptified code. Instead, most of these places are now using the script variable access methods.
This was the last remaining subclass of AActor, meaning that class Actor can now be opened for user-side extensions.
The loop never checked if the item was still valid and would continue to try to use it, even after it was removed from the inventory and destroyed.
As native code this just failed silently, but with the VM it needs to be explicitly checked.
