onItemClick id is incorrect

[davejohncole]

https://github.com/etsy/AndroidStaggeredGrid/blob/master/library/src/main/java/com/etsy/android/grid/ExtendableListView.java#L2744

The position argument to performItemClick is offset by mFirstPosition, but the argument passed to adapter.getItemId() is not offset.

I think the line should be:

performItemClick(view, motionPosition + mFirstPosition, adapter.getItemId(motionPosition + mFirstPosition));

[denizmveli]

Care to send a pull request? Would love to give you credit for your fix.

[davejohncole]

I suppose I should learn how to do that...

[denizmveli]

Fixed by #86. Thanks again!