This finally moves the ParagraphList members of Buffer and InsetText to LyXText (and replaces the ParagraphList * member we've had there by the real thing).
A few smaller modification finally makes LyXText::inset_owner superflous. [So we have only three 'bad' back pointers in the core left: Paragraph::Pimpl_::inset_owner, InsetOld::owner_, and, depending on your point of view, LyXText::bv_owner. We won't be able to do much about the last one for a while, though...] Andre' -- Those who desire to give up Freedom in order to gain Security, will not have, nor do they deserve, either one. (T. Jefferson or B. Franklin or both...)
