Redesign main menu to suit our needs

I redesigned the main menu and added a path to start the game that asks
for the grade level and which game they want to play.
Add problem generator and clean up code

I added a problem generator that will give appropriate random problems
for each grade level and cleaned up some of the old code.
Added the start of the space invaders game
added all other files I changed
Merge branch 'master' of https://github.com/jsaun/SE329_KinderLearn

Conflicts:
	AndroidManifest.xml
	bin/AndroidManifest.xml
	gen/com/se/kinderlearn/R.java
	res/values/strings.xml
Fixed merge problems
I got some graphics working on a background thread
Update to pass grade to SpaceInvaders
updated alm to not crash on navigation
Started work on actually getting gameplay
added moving enemy code
Hooked up touch events and enemies can now be touched