Simple show powerups in use

Could use some tweaking, but it's a start...
Refactor Powerup Confirmation

Get the popup code all in one place for enhancements.
Add Icon to Purchase Confirmation
Refactor Powerup Confirmation

One more adjustment, to prepare the way for keeping a count...
Buy multiple powerups, fixes #34
Switch best and worst suit, fixes #40

Moved around on the statistics screen to make more visual sense.
Tweak the flash speeds, #36
Replay tutorial, closes #4

Option in the Settings to replay the tutorial.  Sets it (temporarily) to
20 rounds, but keeps the current deck. Automatically starts a new game
if needed.
Merge pull request #42 from SariniLynn/develop

Multiple Powerups, Repeat Tutorial