bus config files problem

[ich]

I'm writing a system bus service for which i'd like root (or a config
file owner) to be able to change which users could connect to it.

So i have 3 problems:

Where is the busconfig.dtd?
http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd (found in
other cfg files) does not even exist, and a google search proved
fruitless.

Is there some api to programmatically change the files?

Is there a way to get dbus to reread conf files without restarting?

Changing policy from within a service seems reasonable.  And it would be
pretty lame to have to tell users of a GUI frontend that they have to
bust out a text editor, understand the dtd, edit it by hand, kill, then
restart the dbus system bus and anything attached to it.

help?

michael