_ensureBottomLine() is probably getting called too often

[natejenkins]

and adding a new div under any heading when pressing backspace

[bananaoomarang]

This function seems a little overzealous. If you press backspace in a <li>, the wrapping <{o,u}l> isn't seen as a block level element and a new div is inserted.

[bananaoomarang]

Can't reproduce on a header, though. It needs to have a non-inline element (like a <li>) in it to trigger the insert