Improve readability in the VUops.
Remove giant min/max defines and make their usage more understandable.
Use a function with u32 inputs and make sure all the casts match, because..
Merge pull request #221 from xsacha/vuops-2

Improve readability in the VUops.
Removed a couple of unhelpful comments from today and a bunch from 2003.
Removed unused variables.