On a touch device, if children has bdrag, we cannot scroll parent

[ghost]

I have done an example on jsfiddle : http://jsfiddle.net/ztwqE/4/
When the movement of the scroll starts on the red space, it doesn't work.
When the movement of the scroll starts on the blue space, the scroll works.

[jeremychone]

Need to test with children with drag handle and make sure it allows to scroll content when dragging a non-draghandle area.