r3586: Fix some of the issues with the module init functions.

Both subsystems and modules can now have init functions, which can be
specified in .mk files (INIT_FUNCTION = ...)

The build system will define :
 - SUBSYSTEM_init_static_modules that calls the init functions of all statically compiled modules. Failing to load will generate an error which is not fatal
 - BINARY_init_subsystems that calls the init functions (if defined) for the subsystems the binary depends on

This removes the hack with the "static bool Initialised = " and the
"lazy_init" functions
(This used to be commit 7a8244761b)

source4/lib/socket/socket_unix.c

@@ -273,8 +273,3 @@ const struct socket_ops *socket_unixdom_ops(void)
 {
 	return &unixdom_ops;
 }
-
-NTSTATUS socket_unixdom_init(void)
-{
-	return NT_STATUS_OK;
-}