Allow to setShadow inside PieConfig in-place of throwing unsupported exception

[codevector]

Hi

As High chart library allows to set shadow for pie type, we do not need to throw unsupported exception for setShadow inside pieconfig.

We have verified the same on JSfiddle

http://jsfiddle.net/Fusher/grK2C/
Docs: http://www.highcharts.com/ref/#plotOptions-pie--shadow

Thanks and regards
Surender Singh

[invient-cp]

Thanks for your feedback. I think the latest version of Highcharts supports it for PieConfig as well. I will verify it.