API IsUsableAction

Determine if an action can be used (you have sufficient mana, reagents and the action is not on cooldown).

isUsable, notEnoughMana = IsUsableAction(slot)

Arguments

 * slot : Integer - The action slot to retrieve data for.

Returns

 * isUsable : Flag - Returns 1 if the action is valid for use at present (Does NOT include cooldown or range tests), nil otherwise.
 * notEnoughMana : Flag - Returns 1 if the reason for the action not being usable is because there is not enough mana/rage/energy, nil otherwise.