bug 819027 - remove unneeded performance nsISupports inheritance r=bz, mccr8
bug 841436 - make nsIDocShell inherit from nsIDocShellTreeItem r=bz
bug 841436 - remove nolonger needed qi from nsIDocShell to nsIDocShellTreeItem r=bz
bug 841434 - use a TArray for nsDocLoader::mChildList r=bz
bug 841430 - nuke nsIEditorDocShell r=bz