Fix Issue #3781 (Case sensitive authz).

* subversion/tests/cmdline/authz_tests.py
  (case_sensitive_authz): Removed XFail decorator.

* subversion/include/svn_config.h
  (svn_config_create) : Documented new parameter.
  (svn_config_read)   : Deprecated.
  (svn_config_read2)  : New function prototype, updated documentation.

* subversion/libsvn_subr/config_impl.h
  (svn_config_t): Added a new boolean called section_names_case_sensitive.

* subversion/libsvn_subr/deprecated.c
  (svn_config_read): New function that calls svn_config_read2
                     with section_names_case_sensitive as FALSE.

* subversion/libsvn_subr/config.c
  (svn_config_create): Added a parameter section_names_case_sensitive
                       which is used to initialize the config.
  (find_option, 
   svn_config_set)   : Added logic to make section names case sensitive.

  (svn_config_read)  : Deprecated.

  (svn_config_read2) : New function that deprecates svn_config_read.
                       Accepts a boolean section_names_case_sensitive,
                       and populates the section names case sensitively 
                       if TRUE.

  (read_all, svn_config_merge)     : Fixed callers.

* subversion/libsvn_repos/authz.c,
  subversion/tests/libsvn_subr/cache-test.c,
  subversion/tests/libsvn_subr/config-test.c,
  subversion/tests/cmdline/atomic-ra-revprop-change.c,
  subversion/svnserve/serve.c,
  subversion/libsvn_fs_fs/fs_fs.c

  (svn_repos_authz_read, test_memcache_basic, test_memcache_longkey,
   test_text_retrieval,test_boolean_retrieval, test_has_section,
   construct_config, load_configs, read_config) : Fixed callers.

Patch by: Arwin Arni <arwin{_AT_}collab.net>