Revision 1614052

On the authzperf branch: Hide the svn_authz_t definition from
the headers again. This will allow us to later store prefix tree
data etc. in that structure.

To do this, we change private API signatures where needed and
add a private API to construct an svn_authz_t from svn_config_t.
This involves a bit of code shuffling in authz.c to have a nicer
function grouping.

* subversion/libsvn_repos/repos.h
  (svn_authz_t): Remove definition from header.
  (svn_repos__authz_validate): Rename to ...
  (svn_repos__authz_config_validate): ... this and make it take
                                      a config instead of an authz.
  (svn_repos__create_authz): New svn_authz_t construction API.

* subversion/libsvn_repos/authz.c
  (authz_validate_baton): Move into "validating" section of authz.c.
  (svn_authz_t): Define here now instead of repos.h.
  (svn_repos__authz_validate): Rename, update and move to "private API"
                               section of authz.c.
  (authz_copy_groups): Use a svn_config_t parameter instead of svn_authz_t.
  (svn_repos__retrieve_config): Move to "private API" section of authz.c.
  (svn_repos__create_authz): Implement new private API function.
  (svn_repos__authz_read,
   svn_repos_authz_parse): Read and validate authz as svn_config_t and
                           construct the svn_authz_t as a last step.

* subversion/libsvn_repos/authz_pool.c
  (authz_object_t): Be honest that we effectively only cache a config_t.
  (svn_repos__authz_pool_get): Update.  Cache the authz config_t and
                               construct the svn_authz_t dynamically.