moved play_sound's path functionality to its own function,
play_sound_path.
changed the name play_sound_path returns, and removed SuppressWarnings
annotations in both play_sound_path and play_sound.
play_sound now throws an exception if sound name is invalid. also
changed play_sound_path to play_sound_custom.
fixed function name
renamed the new function!
play_named_sound path is now lowercase instead of uppercase
fixed an if-statement
Merge pull request #192 from TheOctopod/master

Moved play_sound's path functionality to its own function "play_named_sound".