Finish tight/loose list refactor.

Finish tight/loose list refactor.

If this works, you should notice (if you have a modern CSS aware
browser) that the vertical spacing in lists should look more or
less like what you put in.  (E.g. If you put a blank line between two
list items, you'll get more space between them than if you don't.)

TO FIX: I've probably screwed up rendering in the older marginally
CSS-aware browsers, e.g. NS4.  I don't have NS4 installed right now
to play with.  I'll try to play around with that soon...

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@2586 96ab9672-09ca-45d6-a79d-3d69d39ca109