Version Control With Subversion Source

(svn.serverconfig.pathbasedauthz): Rework this "Path-Based
Authorization" section, splitting the one large section into
subsections, and including some useful information about
repository "names" (as used for access rule matching) suggested by
danielsh.

* en/book/ch09-reference.xml
(svn.ref.mod_dav_svn.conf.directives): Add a note about what the
SVNReposName directive does /not/ do.