updated checks in playback control methods for BaseSound class
updated checks in playback control methods for BaseSound class

rblopes/phaser,spayton/phaser,TukekeSoft/phaser,TukekeSoft/phaser,mahill/phaser,englercj/phaser,TukekeSoft/phaser,spayton/phaser,pixelpicosean/phaser,mahill/phaser,photonstorm/phaser,BeanSeed/phaser,photonstorm/phaser,BeanSeed/phaser