Add option to FactorioServer.sendRcon to throw on non-empty responses
from Factorio. This is useful for detecting errors returned by commands
that should not have a response.
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.