Revamp of looting code

[wallabra]

Besides the different (more flexible) algorithm for determining how much loot should be spawned, I have also integrated your other refactors and changes in your latest looting commit, making this branch compatible with the master branch, and incorporating fixes in your commit 00e9335, such as the differentiation between droppable HDPickups and generic Actor spawns, or the support for Scarcity.

One important caveat is that this does, yet again, change the meaning of UaS_LootingFactor, and it adds new CVars that further configure the looting process, which may be overwhelming for players (especially the ones directly relating to the RNG distribution - those might be better off ).

[wallabra]

I will make it simpler and hardcode some of the settings. The new distribution is still more flexible to work with. It isn't as complex as it seems; the use of mathematical functions is scary, but they simply make a curve shape that makes smaller loot amounts more common than larger ones. That is, it maps an uniform random value to this curve.

[caligari87]

Okay, so to be clear: I already worked out a solution that I like and I'm just not interested in doing it this way.

[wallabra]

That's fair enough, thank you.