New ideas regarding CIF format:

- use data_global and/or global_ sections for storing information
  common to all datablocks within the CIF file. Write cif_globalise
  and cif_unglobalise scripts.

- Define a simplier, line-oriented format based on CIF and CIF
  dictionaries, capable of 1:1 faithful roundtrip. The name for the
  new format might be "Linear C" :). Write a cif2linc script. The
  format would also reintroduce the end-of-loop tokens.

+ Suggest using prefixed in ';'-delimited text fields, to make 'CIF
  within CIF' representation possible.

- Suggest reintroducing stop_ or similar end-of-loop and end-of-line
  tokens.

- Suggest metda-data comments; '#CIF-ENCODING: latin1' might indicate
  what character encoding is used in the CIF file.
