Make find_repos() fit to be used in a repository pool, i.e. without
a specific server baton. 

* subversion/svnserve/server.h
  (repository_t): drop cfg member;
                  add members sasl params stored in the svnserve.cfg

* subversion/svnserve/cyrus_auth.c
  (cyrus_auth_request): take the sasl params from the repository_t struct

* subversion/svnserve/serve.c
  (find_repos): replace server baton with individual parameters;
                pass cfg in as optional parameter;
                read SASL settings from config file as well;
                defer "no access" test to caller
  (serve): update caller; do "no access" test here

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1530123 13f79535-47bb-0310-9956-ffa450edef68