* spawn.cc (spawn_guts): Call CreateProcess while impersonated,

	* spawn.cc (spawn_guts): Call CreateProcess while impersonated,
	when the real {u,g}ids and the groups are original.
	Move RevertToSelf and ImpersonateLoggedOnUser to the main line.
	* uinfo.cc (uinfo_init): Reorganize. If CreateProcess was called
	while impersonated, preserve the uids and gids and call
	ImpersonateLoggedOnUser. Preserve the uids and gids on Win9X.

	* exceptions.cc (error_start_init): Quote the pgm in the command.