Added basic UI layout
Missed file from last commit
Added a dummy problem.
Added level complete popup
Merge branch 'david-game-engine' into development

Conflicts:
	Social Solver/Social Solver.xcodeproj/project.pbxproj
	Social Solver/Social Solver.xcodeproj/project.xcworkspace/xcuserdata/dwoods.xcuserdatad/UserInterfaceState.xcuserstate

Merging partial completion of the game engine to avoid a large commit later
Game engine currently has dummy problems, detects correct vs. incorrect answers and can display the problem image
TODO: Allow playing of a sequence of problems.
- Store problems in a database
- Allow video to play during problems