Bug 1362119 - part 1 - Moving dom/base/Script{Loader,Element}.* in dom/script, r=ehsan

This patch does these things:

1. it moves nsScriptElement, nsScriptLoader, ScriptSettings, nsIScriptElement
   and nsIScriptLoaderObserver in dom/script
2. it renames nsScriptElement to mozilla::dom::ScriptElement
3. it renames nsScriptLaoder to mozilla::dom::ScriptLoader

parser/html/nsHtml5DocumentBuilder.cpp

@@ -8,9 +8,9 @@
 
 #include "nsIStyleSheetLinkingElement.h"
 #include "nsStyleLinkElement.h"
-#include "nsScriptLoader.h"
 #include "nsIHTMLDocument.h"
 #include "nsNameSpaceManager.h"
+#include "mozilla/dom/ScriptLoader.h"
 
 NS_IMPL_CYCLE_COLLECTION_INHERITED(nsHtml5DocumentBuilder, nsContentSink,
                                    mOwnedElements)