Externs were updated due to new version of CreateJS.

Externs were updated due to new version of CreateJS. EaselJS 0.6.0 ->
0.7.0, TweenJS 0.4.0 -> 0.5.0, SoundJS 0.4.0 -> 0.5.0, PreloadJS 0.3.0
-> 0.4.0