[b43] Heave uses physical power, not Dex as claimed

[tiger_eye]

The description for field-control/Heave claims the knockback chance increases with Dex. However, it appears to actually use combatPhysicalpower. The field control tree uses Dex as the requirements, so which should it be: Dex, accuracy, physical power, or whichever is greater (between accuracy and physical power)?