Increased maxpoly from 16 to 128 in Synthonico

Max poly allows more effects at once. Most noticeable when using sequencer playback where notes will be skipped when maxpoly is reached.

Adjusted Synthonico's ABC notation conversion to produce more stable files. Added to Math Marines, so that A and D keys now cause a simulated strafe movement.

Added a keypad and adjusted its position.

Added a starfield background that produces random colored stars.