* test/data/auth/*: adapt to changes

	* dbus/dbus-auth-script.c (_dbus_auth_script_run): add
	USERID_BASE64 and change USERNAME_BASE64 to put in username not
	userid

	* dbus/dbus-keyring.c (_dbus_keyring_validate_context): prevent
	more stuff from being in a context name, to make the protocol
	simpler to deal with

	* dbus/dbus-errors.c (dbus_error_has_name): new function
	(dbus_error_is_set): new function

	* dbus/dbus-auth.c: replace DBUS_STUPID_TEST_MECH auth
	with DBUS_COOKIE_SHA1, implement DBUS_COOKIE_SHA1

	* dbus/dbus-connection.c (dbus_connection_flush): also read
	messages during a flush operation

	* dbus/Makefile.am: remove dbus-md5 since it isn't currently used.