- Cleaned up, renamed and reordered functions,

- Cleaned up, renamed and reordered functions,
  improved comments
- Removed my_strsep
- Replaced globalflag with a general flags int
  that holds PCRS_GLOBAL, PCRS_SUCCESS, and PCRS_TRIVIAL
- Introduced trivial option that will prevent pcrs
  from honouring backreferences in the substitute,
  which is useful for large substitutes that are
  red in from somewhere and saves the pain of escaping
  the backrefs
- Introduced convenience function pcrs_free_joblist()
- Split pcrs_make_job() into pcrs_compile(), which still
  takes a complete s/// comand as argument and parses it,
  and a new function pcrs_make_job, which takes the
  three separate components. This should make for a
  much friendlier frontend.
- Removed create_pcrs_job() which was useless
- Fixed a bug in pcrs_execute
- Success flag is now handled by pcrs instead of user
- Removed logentry from cancelled commit