Froggy 0.11 update

Updated Froggy to v0.11.

• game now has four levels with level completion/game over mechanics
• added level transition mechanics
• added player score
• added proper menus
• improved collisions
• various bug fixes
• increased base resolution to 270 pixels high

This version features an experiment with trees displayed from an overhead perspective. When the player moves under the tree, the tree switches to a transparent view.