Melee practice and message tweaks

The order of melee practice now depends on weapon type.  This should stop bashing skill from hogging all the XP, since every melee attack, regardless of weapon type, has some significant bashing damage.

Damage-based piercing skill practice threshold is lowered, as piercing weapons tend to do less damage (cut damage / 4).

Changed the melee verb to display according to weapon type, rather than damage type.