Add startup event to the Clusterio module API which is raised at startup
of a Factorio server. This is to server as a replacement for the
on_init and on_configuration_changed events which cannot be used in
modules.
Adds clusterio_patch_number global from the patcher in order to
implement this. This is a number that's incremented every time the save
is patched.
Change module loading to use a module.json file describing the module
and patch in all files in a directory path passed to the patcher instead
of having to pass the files names and their content. This allows the
specification of which files should be passed to the event_handler lib
and an easy implementation of loading stand alone modules.