Balance Update

This update reworks the mana system.  The tutorial has not been updated to reflect the new changes, that will come after we get some feedback.

• Cards no longer cost mana to play.
• You can draw a card from the deck for 2 mana by clicking on the draw pile.
• You now start with 3 mana.
• Enemy abilities have been reworked, mostly to be easier to read.

Let us know what you think about the update.  Thanks for playing!