Implement a --show-passwords option for 'svnauth list', and hide passwords by default.
Implement a --show-passwords option for 'svnauth list', and hide passwords
by default.

Currently, encrypted passwords are treated the same way as plaintext passwords.
This might change later.

* subversion/svnauth/svnauth.c
  (svnauth_opt_state): Add show_passwords option.
  (svn_cl__longopt_t): Add opt_show_passwords.
  (cmd_table): Add --show-passwords to 'svnauth list'.
  (options_table): Add --show-passwords.
  (list_credentials): Rename 'cleanup_baton' to 'baton' and expect the option
   state in baton. Don't show passwords unless --show-passwords was given.
  (subcommand_list): Pass opt_state as baton to the list_credentials callback.
  (sub_main): Handle --show-passwords option.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1500830 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion