the recent changes made to DT_Util.namespace().

e.g. GET http://www.zope.org:8080/ is legal, but medusa was not cleaning this
up to a URI of /.

The REQUEST regex was converted to a re format to accomplish this

ZClasses derived from Item_w__name__ (such as DTMLMethods).

Merged new help content changes into the trunk. This completes the switch form DTML to STX. Also includes misc fixes to support help system.