Reduce storage requirements

[sverhoeven]

We could accept gzipped input files and write gzipped fitted models (fit_N.pdb).

• Input files
  • template.pdb.gz
  • tempalte.cif.gz
  • target.map.gz
  • target.mrc.gz
  • target.xplor.gz
  • target.cns.gz
• Output files (probably toggled with an cli arg, to prevent breaking changes)
  • fit_N.pdb.gz
  • lcc.mrc.gz

[sverhoeven]

Also see #88