Prevent adding content to aliens in IE

The phantoms prevent direct clicking into aliens,
and the recent selection changes prevent keyboard
navigation into aliens, but one issue remained.
Clicking to place the cursor just after an alien
would actually focus within the alien. Typing
modified the alien content. By nesting ce="true"
within ce="true", IE ceases this behavior.

Dragging state is now set to false when blurring
the document. The mouseup event sets dragging to
false, but the event is cancelled because blur
happens between mousedown and mouseup. Phantom
display logic uses on this property.

Change-Id: I162dea89838756fd28d63ff66cc4a5e5bda2873a
Merge "Prevent adding content to aliens in IE"