Supports chrome browser (v11) on google tv

i've tested this project on chrome browser on google tv(v11, logitech revue). unfortunately it had not work. so i've changed code about define property. it's just reporting for issue below.

add setter to avoid exception [1] and using defineProperty instead of __defineGetter__ for inheritance error [2]

[1]: TypeError: Cannot set property interationTIme of par 0-NaN(0@0) [par 1-undefined (0 @-0.994)[] ] which has only a getter
[2]: can't found super object (ParGroup) if it's using __defineGetter__