-Add background image support in TextItem class (TextItem can now take in a Background object)
-Tweak rocket height to work better with our current number of levels
-Much better feedback on right/wrong answer (color- and image-coded)
-Add multi-line support in TextItem class (now takes in an array for text, each element is a line)
-Better looking default colors for TextItem
-Better looking beaker fill/text
-Make Reset/Back to Menu/Current Level/Score elements stand out more
-Add image to gameplay screen background, currently same as menu background