(svn_config_ensure): Reorganize documentation in default servers file, and add notes about svn-tunnel-agent.
(svn_config_ensure): Reorganize documentation in default servers
file, and add notes about svn-tunnel-agent.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion