bmCHOChainList is an array listing all chains not in SEQRES (not in chainList)
	or if no header, all chains not protein or nucleic.
	It includes DUPLICATES, e.g. B, B1, B2, B3 in 1f8b.
bmCHOChainsTotal
	chainList has chains in AU.
	bmChainList has chains in BU.

To debug CHO list in Chain Details:
  help3.js #11, top.js #41, moltab.js #90.

choChainIDList is an array of AU chain IDs only, grouped by seqid.

HEADER
in top.js  if (!pdbNoHeader) choChainIDList = groupBySeqID(deRange(rangeify(bmCHOChainList)));
	groupBySeqID() is in moltab.js

NO HEADER
in moltab.js in getNoHeaderChains():
	chainList = groupBySeqID(array of chains type protein/dna/rna/nucleic)
	choChainIDList = groupBySeqID(array of other chains);