[REDESIGN] New code for line breaking in nested inlines

[Karen Lease <kl...@club-internet.fr>]

Foppeuses, Foppeurs,

I've added some new stuff to the development branch to show how the
BreakPoss strategy would handle nested inlines. It doesn't do anything
with blocks in inlines yet. For the moment, FOs are creating "BP" style
layout managers for Inline, Text and Line.

There's a new inline area class "InlineParent" which contains child
inline areas. I've only modified the XML renderer for the moment to
handle this.
Also, the vertical alginment stuff is currently disabled, since I was
only concentrating on handling breaks in nested areas and correctly
propogating position information up to the Line LM.

It should be able to get through the attached test case without
crashing.

Final warning: I sort of screwed up my commit. CVS looks ok, but some of
the commit messages didn't get mailed. Please yell if you notice any
problems. Sorry :-((

Regards,
Karen