Merge branch 'mindslayercorrections' into 'master'

Mindslayercorrections

Adds rounding to Augmentation.
Clarifies the psionic combat modifier.
Corrects the way the psionic combat modifier is handled in combat.lua (and hence the weapon tooltips).
Buffs the base mindstars slightly and slightly nerfs artifact mindstars to reduce the huge gap.
Adds an icon for Psionic Maelstrom, though Nagyhal says he can make it better.