This adds two new enums to persistent sounds which can be utilized by scripts.
1. OS_PLAY_ON_PLAYER, which allows persistent sounds to play on the player's ship.
2. OS_LOOPING_DISABLED, which allows the scripter to set the sound to play once and not have to then call `removeSound` later. Very handy for playing an assigned sound once with one line.
Tested and everything works as expected.