Fraction overlay now overlays on top of canvas, acting as a separate
game area the player must navigate out of by answering or ignoring
the fraction addition.

Fraction addition now accepts any fraction values that reduce to the
correct answer as player input.

Tooltips got a facelift.
Fixed fuel needle jittering due to fraction inputs.

Cash and Parcel tooltips now show when hovering over their
respective text areas as well as the images.
Merge pull request #146 from Seneca-CDOT/issue137

Fraction overlay now overlays on top of canvas, acting as a separate