insertOrderList: implement unlistifying
insertOrderedList: yosin's review
Merge pull request #48 from hajimehoshi/issue-46

insertOrderList: implement unlistifying
Introduce |editing.nodes.canContainRangeEndPoint(node)| for "createLink" command.
Revise |Editor.prototype.getDomSelection()| to handle |Seleciton.getRangeAt(0).startContainer| and |Seleciton.anchorNode| have different value.
Example: <div>^1<a>2</a>|</div>, range.start = DIV,0, selection.anchor="1",0
See editing/style/apply-style-atomic.html
createLink: Implement atomic element, which are !Node::canContainRangeEndPoint().
createLink: Tidying up "create_link_command.js".
createLink: Add test case for font/@size and "font-size" CSS property.