ng-cancel-drag now works with dynamic child elements

[sebhofmann]

I have a tree like ngDrag > select > option and the options are generated with ng-option, so there is no ways to set the ng-cancel-drag for the options. If the options have no ng-cancel-drag firefox is buggy when clicking on a option.

[nmarcetic]

What about this ? Its not merged yet... and I am confirming this as a fix. I have a same problem and I just tested this for dynamic child elements, it works! Can someone pls merge this ? Thanks @paschty