Fix lower notes not playing all the way through

The time that each emitter will remain active for now depends on the pitch of the sound -- lower sounds will remain for longer, and vice-versa.

Author: Bentroen

scripts/play_sound/play_sound.gml

@@ -26,5 +26,5 @@ audio_play_sound_on(emitter,ins.sound, 0, 0)
 //Schedule emitter to be deleted from memory
 newemitter = ds_list_create()
 ds_list_add(newemitter,emitter) //store emitter id
-ds_list_add(newemitter, (audio_sound_length(ins.sound) * 600000) + get_timer()) //store moment of which the emitter should be removed
+ds_list_add(newemitter, (audio_sound_length(ins.sound) * 1000000 * (1/audio_emitter_get_pitch(emitter))) + get_timer()) //store moment at which the emitter should be removed
 ds_list_add(emitters_to_remove, newemitter)