[cssom-view][matrix] Introduce DOMRectLiteral dictionary for DOMRect?

In  
http://lists.w3.org/Archives/Public/public-script-coord/2013JulSep/0690.html  
it was suggested that APIs accepting DOMRect as input should also allow an  
object with the right properties -- like we already do for  
DOMPoint/DOMPointLiteral.

I guess the same might apply to DOMQuad and DOMMatrix as well, although  
they are more complicated than DOMPoint and DOMRect. DOMQuad's attributes  
are objects. DOMMatrix's constructor takes several different inputs which  
would make sense to support as input for anything that expects a DOMMatrix  
if the argument is that the constructor shouldn't have to be invoked.

-- 
Simon Pieters
Opera Software