Shortlist of cleanups to think about at some stage:
===================================================
* Make error handling (and thus especially touching errno) more consistent.
* I assumed that most malloc() implementations set errno on failure, but
  for klibc for example, that is not true .. create a malloc wrapper to
  make sure errno=ENOMEM on failure.
* Split generate_stage2() and co to handle a function at a time if not too
  slow .. this will enable us to use less memory.
* Think about using linked lists to the actual dependencies, rather than
  string lists for service_info_t->depend_info.  This might need a lot of
  rework, but could also safe us some memory, and lower trashing.