Adding new features and bugfixes.

- Adding a new method "drawSprite" to draw sprites.
- Adding a new method "frameSyncShowFreeRAM" to display the free rad using the extra LEDs.
- Adding a new parameter "priority" for playing sounds.
- Adding methods "getScreenWidth()" and "getScreenHeight()" to get the current screen dimensions.
- Change the type for x/y coordinates to int8_t. Simpler to work with negative numbers.
- Adding sound tokens "PlayWithPauseX" to play a sound with a small pause to the next note.
- Adding sound tokens "PlayStaccatoX" to play a short sound to keep the right timing.
- Change some methods to inline.