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

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 7a8244761bfdfdfb48f8264d76951ebdfbf7bd8a)