cleaned neume drawing code
cleaned neume drawing code

cleaned up neume component y position (in pixels) calculations

DDMAL/Neon.js,avorio/Neon.js,DDMAL/Neon.js,avorio/Neon.js,avorio/Neon.js,DDMAL/Neon.js,DDMAL/Neon.js,avorio/Neon.js