Changed Fraction and added new methods
added isSelectionCorrect function
finalized additional changes in fractions
Merge remote-tracking branch 'origin/Henry' into questionTestBranch
minor ui file
Accessors on QuestionObject
utility functions to manipulate vectors
fixed isSelectionCorrect method
Merge remote-tracking branch 'origin/Henry' into jason

Conflicts:
	LinEqGame/LinEqGame/MyScene.m
Merge remote-tracking branch 'origin/PhilSelectorButtons' into jason

Conflicts:
	LinEqGame/LinEqGame.xcodeproj/project.xcworkspace/xcuserdata/pliao.xcuserdatad/UserInterfaceState.xcuserstate
	LinEqGame/LinEqGame/MyScene.m
	LinEqGame/LinEqGame/Selectors/Selector.m