Moved stuff around again
Fixed up states system
Placeholder menu state created
Added audio functionality to test whether tracks are already playing
 - triggerEffect and playTrack will not restart track if it is already playing by default, but will if passed true as a second parameter
Added stateExit callback for states
Added main menu music
Added functions to stop all sfx, tracks or both
Added menu sfx from freesfx
Added music and sfx to menu