Changes and additions from ASTRAL 2.07 to 2.08:

RAF version 0.03:

We have updated the format of the RAF maps, which summarize the
SEQRES - ATOM relationship within each protein chain in a form that
can be rapidly parsed in most computer languages.  Residues present in
the SEQRES but missing from the ATOM records are now assigned residue
identifiers by the PDB, and documented in the mmCIF and XML format
files.  We now include these identifiers in the RAF format instead
of the letters ("B", "M", and "E") that we previous used to indicate
missing identifiers.