Update and tag for 0.3.0 release

Each window has its own audio engine
Add mute toggle for audio engine
Add call to parent constructor for each Sort subclass
Each window has its own canvas
Calculate bar width and extra space each frame
Each canvas has its own highlight color
Add ModifierMenuItem for simplier menus
Pass reference of audio engine to Number
Randomize uses window's maximum
Move majority of code in main class to window and canvas