FLUID-4599: More fixes for the IE event pass-thru issue to ignore the click on the controller bar and the transcript menu.
FLUID-4599: Removed the redudant mouse position check with Y value.
FLUID-4599: Removed the not-in-use variable.
FLUID-4599: More fix for IE event pass-thru issue: stopped the controller from bubbling up the mousedown event to the parent overlay.