Doesn't distinguish which button is pushed

[keithleeds]

Either the left or right button causes the drag, effectively disabling a right-click for a context menu. Needs to test MouseEvent.button for zero (assuming using the left button to drag).
Would be nice to have a slight delay before drag engages to ignore click events.

[keithleeds]

Simply adding:
if(e.button!==0)
return;
in the el.delegate(... routine fixed it.

[jbaird-op]

@keithleeds Feel free to submit a pull request.
cheers!