fix deadlock when dbus-daemon could not start up

fix deadlock when dbus-daemon could not start up

windbus:r811: apply patch by Thorvald Natvig to fix endless loop when _dbus_get_autolaunch_shm got called and the dbus-daemon failed to start up.
* if launching for some reason fails, set an error message
* _dbus_get_autolaunch_shm will abort getting the shared memory after 20 attempts (2 seconds)
* _dbus_get_autolaunch_address checks if the return state of WaitForInputIdle before calling _dbus_get_autolaunch_shm.

windbus:r812: remove WaitForInputIdle as it doesn't work in non-console mode
(cherry picked from commit 363fd736556219bad77c4b217e051b7983dc34e9)