Prep for 3.1.9 tag (sync from QUT SVN)

Changes include:
-  bb:NG tags
-  Doctype fix (for IE8 quirks-mode woes)
-  Fixed various selectors for 9.1sp9
-  Remove iFrame tweaks - existing instances of these will be redirected
to the new 'Load webpage as content' tweak (compatible with legacy
IFRAME and Load Subsite tweaks)
-  Probably other some stuff too
missed one