On the authzperf branch:  Prepare authz code to switch from svn_config_t
to the next-gen authz model.

This involves switching internal functions to return streams and only
produce svn_config_t as a last step.  We also switch private interfaces
to the two-pool paradigm and remove private API that is not needed ATM.
Finally, temporarily disable the authz_pool logic.

* subversion/include/private/svn_repos_private.h
  (svn_repos__retrieve_config): Switch to two-pool paradigm.

* subversion/libsvn_repos/repos.h
  (svn_repos__authz_read): Same.
  (svn_repos__authz_config_validate,
   svn_repos__create_authz): Drop these.

* subversion/libsvn_repos/authz.c
  (authz_retrieve_config_repo): Return a stream instead of a parsed config
                                and drop then now unused CASE_SENSITIVE
                                parameter.
  (authz_retrieve_config_file): New function with similar to the previous
                                but reading from the local file system.
  (retrieve_config): New, factored out from svn_repos__retrieve_config,
                     combining the above two.
  (svn_repos__authz_config_validate,
   svn_repos__create_authz): Rename to ...
  (authz_config_validate,
   create_authz): ... these as they are no longer exposed through a header.

  (svn_repos__retrieve_config): Update and simplify.  Do the config parsing
                                only here at the interface.
  (svn_repos__authz_read): Update.  Do the config parsing only here at the
                           interface.
  (svn_repos_authz_read2,
   svn_repos_authz_parse): Update callers.

* subversion/libsvn_repos/config_pool.c
  (svn_repos__config_pool_get): Update caller.

* subversion/libsvn_repos/deprecated.c
  (svn_repos_authz_read): Ditto.

* subversion/libsvn_repos/authz_pool.c
  (svn_repos__authz_pool_get): Bypass config-based logic and always read
                               authz data anew.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/authzperf@1617083 13f79535-47bb-0310-9956-ffa450edef68