WIP: Up Your Sleeve Powerup

Cards may be selected and purchased, and they will be stored, but they
cannot yet be used in play.
Refactor powerup icon

... to give one that cannot be clicked to use.
Up Your Sleeve Powerup

Use and consume the cards.
Remove ghost powerup in tray

.. from storage of the cards purchased via powerup.
Fit powerup cards into selection screen

... at the same size and position as in the initial purchase popup.
Return powerup card to tray

Allow the player to touch an Up Your Sleeve card to return it to the
tray.
Return invalid powerup card to tray

Automatically return a special card when its requirements are not met.
Handle many powerups

Scroll to view the rest.
Merge pull request #37 from SariniLynn/develop

Up Your Sleeve