The sharpen skill allows an experienced warrior the chance to improve
his weapon by sharpening its blade. Success is based upon the warriors
level, sharpen skill %, dexterity, and strength. Failure may result
in no change in the weapon, or the weapon may be dulled beyond repair.
If successful, the weapon is given the "sharp" flag, and in extremely
*rare* instances, a warrior may create a "vorpal" weapon.
Syntax: sharpen <weapon>