sort / reverse modify arrays in-place

[odino]

possibly strings as well -- and there might be some other functions that modify things in place themselves...shuffle / flatten etc all work on a copy.

It'd be good to just unify this behavior...

[mcampbell]

While unifying is great, I'd unify on the "returns a copy of the modified array/string" direction. If you ever want to get into threading or anything, immutability goes a long way in eliminating all sorts of race conditions