Added duration property to BaseSound class
Added duration property to BaseSound class

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