Changes and additions from ASTRAL 1.61 to 1.63:

* PDB chain sets

Bug fix: Removed extra '.' characters which were present in some PDB
chain sequences.  (Thanks to Martin Madera for reporting this.)
Clarification: Sequences are derived from SEQRES records of PDB
chains.  However, as is the case for SCOP domain sequences, residues
at the beginning and ends of the sequences with no atomic coordinates
are removed.

* Script improvements

Scripts which retrieve individual sequences or PDB-style files now
accept SCOP sun IDs as well as sccs IDs.  Also, to facilitate
automatic retrieval of data by scripts, files can now be retrieved in
text or HTML format.  PDB-style files may also be retrieved with the
"chemical/x-pdb" MIME type for appropriate handling by web browsers.

* PDB-style file improvements

The header (REMARK records) format has been cleaned up, and AEROSPACI
and SPACI scores are now part of the headers.  There is a new
"Data-updated-release" header which indicates the last ASTRAL version
in which the non-header (i.e. ATOM, MODEL, etc) data was changed.  A
file summarizing the Data-updated-release version for every current
PDB-style file is also available, called pdbstyle-updated-1.63.txt.
This eliminates the need to download PDB-style files for which the
data has not changed between releases.

* Bug fixes

Several cases of microheterogeneity were eliminated from the RAF files
and sequences.  (Thanks to David E. Konerding for finding them.)