* dbus/dbus-test.c: enclose more of the file in the
	DBUS_BUILD_TESTS check.

	* dbus/dbus-sysdeps-pthread.c (PTHREAD_CHECK): fix for
	DBUS_DISABLE_ASSERT case.

	* dbus/dbus-connection.c (dbus_connection_get_unix_user): document
	that it only works on the server side

	* dbus/dbus-bus.c: add a global lock covering the BusData we
	attach to each connection
	(internal_bus_get): lock our access to the BusData
	(dbus_bus_register): lock the entire registration process
	with _DBUS_LOCK(bus_datas). If we get the lock and
	registration is already complete, silently return (vs. previous
	behavior of aborting).
	(dbus_bus_set_unique_name): lock the BusData
	(dbus_bus_get_unique_name): lock the BusData