Beginning Creatures implementation

Laid out groundwork for creature cards, a check is made when a creature
card is played to see if the player has enough lessons to play it.

-Misc: Added a small glow effect when the player hovers over a clickable
card with their mouse, maybe do this with the deck as well.

TO DO:
*Implement discard pile for when certain creatures call for lessons to
be discarded in order to be played.

*Figure out positioning constants and offsets for creature cards and
discard pile
Continue creatures implementation

Created CardStacks for discard pile and in-play creatures
All checks for creature cards are now in place
TODO: Positioning constants and tweening.
fixedcommit
fixing merge conflict
Removed unnecessary function

Player.checkLessonTypes is unneeded now as the hasType array as been
converted to count the number of lessons as opposed to just keeping a
true/false value for each one. This changes our function to a one-liner
which we can simply inline in the playLesson function.
Cleaned up some comments
playCreature returns boolean
CardStack contains function
Discard lesson function
Tooltip titles show required lessons

Titles increased in size, font style changed to bold.
Creatures Implemented!
Merge pull request #1 from StefanoFiumara/Develop

Move Implemented Creatures into master