Few changes:
- Fully finish implementation of bonus tiles. First they are yellow blocks and when hit from the bottom by the player they 'bounce' up a few pixels, then go back down, turn brown and show a surprise to the player (currently only implemented a new coin). TODO: Only trigger action when tile is hit from the bottom.
- Implemented Tile-wide boolean method called OnCollision which is called when any unit collides with a tile that has its own class. This is required because we can't add them as collidable gameobjects in the Game class because then they will never detect the collision properly as it never runs through. The method returns true if they should not allow movement through the object and false if it's the other way around. This also means that special tile-handling is now handled inside their own class rather than in the Game class by typeid.
- Holding Shift and releasing the 'T' key will now kill all currently alive enemies.
- Placement of coins is now slightly randomized so they don't all move synchronized.
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