* bus/selinux.c (bus_selinux_init): Split into two functions,
	bus_selinux_pre_init and bus_selinux_post_init.
	(bus_selinux_pre_init): Just determine whether SELinux is
	enabled.
	(bus_selinux_post_init): Do everything else.

	* bus/main.c (main): Call bus_selinux_pre_init before parsing
	config file, and bus_selinux_post_init after.  This ensures that
	we don't lose the policyreload notification thread that
	bus_selinux_init created before forking previously.

	* bus/test-main.c (test_pre_hook): Update for split.