Implement asymmetric border widths.
auto merge of #681 : metajack/servo/asymmetric-borders, r=pcwalton
Add a getter of 'document.head' according to HTML spec.
Add a getter and a setter of 'document.title' according to HTML spec.
Modify the test file.
Implement element.tagName
auto merge of #658 : june0cho/servo/docBindings, r=jdm

Add a getter for document.head and document.title.

Like in the modified test (document.title="changed title"), setters for elements doesn't seem to be called.
auto merge of #688 : sonwow/servo/element, r=jdm

Implement `dom::element::Element::TagName` for autogenerate DOM bindings.
Generate bindings for HTMLBodyElement
auto merge of #691 : june0cho/servo/genBinding_Body, r=jdm

I commented out the last line of HTMLBodyElement.webidl, 'HTMLBodyElement implements WindowEventHandlers;' in order to avoid compile error.
Generate HTMLIFrameElement bindings.