* subversion/clients/cmdline/main.c (svn_cl__options): Add "no_auth_cache" option. (svn_cl__cmd_table): Support the new option in many commands. (main): Notice the option, set opt_state accordingly.
* subversion/include/svn_client.h (svn_client_auth_baton_t): Remove overwrite field, split into two new boolean fields store_auth_info and got_new_auth_info.
* subversion/clients/cmdline/prompt.c (svn_cl__make_auth_baton): Set the new fields accordingly.
* subversion/libsvn_client/auth.c (get_username, get_password): Adjust for above; also, tighten logic. (maybe_store_username, maybe_store_password): Replace store_username and store_password respectively. Put config conditionalization into the latter. All callers changed. (store_user_and_pass): Don't do config conditionalization here, maybe_store_password takes care of it now.