r12494: Support loading modules from .so files for most subsystems.

r12494: Support loading modules from .so files for most subsystems.
We now use a different system for initializing the modules for a subsystem.
Most subsystems now have an init function that looks something like this:

	init_module_fn static_init[] = STATIC_AUTH_MODULES;
	init_module_fn *shared_init = load_samba_modules(NULL, "auth");

	run_init_functions(static_init);
	run_init_functions(shared_init);

	talloc_free(shared_init);

I hope to eliminate the other init functions later on (the
init_programname_subsystems; defines).