Fixed Low Checks/Updated Consumables

Added 'isLow' function.
Deleted 'manaPot' from Items class(as Katarina doesn't even use Mana).
Deleted 'mpSlot'.
Added checks for Zhonya/Wooglets and HP Pots.

Indented like you did.
Merge pull request #4 from RoachxD/patch-2

Fixed Low Checks/Updated Consumables