libsvn_ra_xml

I've just realized that libsvn_client is structured incorrectly. It deals
directly with XML files. tsk tsk... none of that will apply when we want to
drop libsvn_ra_dav in there.

I propose shifting out the XML code to libsvn_ra_xml. Thus, if we want to
use XML as the input/output/transport mechanism, then *that* RA library gets
loaded to do it.

Thoughts?

Cheers,
-g

-- 
Greg Stein, http://www.lyra.org/