added movement to player controller
finished sprite animations
got input/movement/animations working with playercontroller
Screen Logic and Basic Menu Navigation

Created Screen classes for all of the different screens, connected them
all together logically, and added a primitive input handler for
keyboard/gamepad navigation of the menus.
added basic enemy AI
Merge remote-tracking branch 'origin/master'

Conflicts:

	FrogsVToads/FrogsVToads/FrogsVToadsContent/FrogsVToadsContent.contentproj
adjusted frogs, started damage functionality
Added physical constants and physical properties classes
Merge branch 'master' of https://github.com/jdcook/FrogsVToads
Network Game for learning

Network game for testing how to do networking.
csproj update

update csproj to include the networking folder
Merge branch 'Networking' of https://github.com/jdcook/FrogsVToads into Networking