Issue #1375 - Stop largely using the parser service

This is based on Bug 1395828

* Add nsHTMLElement::IsBlock()
* Rename nsHTMLTags methods
* Remove AssertParserServiceIsCorrect()
* Remove most uses of nsIParserService/nsParserService

editor/libeditor/EditorBase.cpp

@@ -107,16 +107,12 @@
 #include "prtime.h"                     // for PR_Now
 
 class nsIOutputStream;
-class nsIParserService;
 class nsITransferable;
 
 #ifdef DEBUG
 #include "nsIDOMHTMLDocument.h"         // for nsIDOMHTMLDocument
 #endif
 
-// Defined in nsEditorRegistration.cpp
-extern nsIParserService *sParserService;
-
 namespace mozilla {
 
 using namespace dom;