* dbus/dbus-string.c (_dbus_string_pop_line): fix this not to
	think an empty line is the end of the file.
	Also, fix some whitespace.

	* dbus/dbus-string-util.c: add more tests for
	_dbus_string_pop_line() revealing that it thinks an empty line is
	the end of the file, which broke dbus-auth-script.c so
	it didn't really run the scripts

	* dbus/dbus-auth.c: add ANONYMOUS mechanism

	* dbus/dbus-auth-script.c (_dbus_auth_script_run): fix to detect
	an empty/no-op auth script; add commands to check that we have or
	don't have the expected credentials