Small Maxwell improvements

[FourthLess]

I like the way his shadows work but I think they could use some improvements to make them feel worth using, here's what I think they need:

- No time limit on how long they can live

Always thought this one is a bit silly to have especially considering the next point

- Give Shadow clones some small hp regeneration

They're pretty frail and I don't want them to be tanky so I think regen would be really nice especially since they feel like they should stay by your side from day to day small fights and mundane tasks

Smaller tweaks that I don't think are must have but would improve experience using them quite a bit:

- Make them fire immune

Pretty self explanatory, they're shadows after all

- Give their brains a high priority function that would make them abandon their task and follow you if you go too far away from them

That would give you a bit more control over them, especially would be nice when things go too bad and you would like them to stop attacking

- Maybe reduce their sanity cost a bit so you could have one more shadow at max? 

Just a thought, current number is fine enough I think. 

[Pomato]

Can the shadow puppets get a max damage taken threshold just to make them tankier?

And maybe get rid of their kiting ability. It barely works out well from my personal experience.