Added two cardviews to the GameScreenActivity. When the GameDisplayView is clicked in this activity, it hides, and these two view show the environment and creature cards.
Fixed some casting errors in Environment.
Added a test and testsuite, but may delete them because I hate them and they aren't super useful.
Improved GameStateDisplay to show current creature population and size.

Because of changes in gameplay, the below changes happened.
Cards is now a superclass with PlayerCards and EnvironmentCards as subclasses.
This necessitates PlayerDeck and EnvironmentDeck which are not subclassed.
These changes ripple through many places.