minor, trial, use different designators for different lowercase/uppercase differences
revert, use U+xxU for case-maintaining codes and u+xxu for downcased sequences
minor, provide an upcase-code routine (cod2upc()) by iterating over genmapn's
Merge branch 'tool/glanz'

* tool/glanz:
  minor, provide an upcase-code routine (cod2upc()) by iterating over genmapn's
  revert, use U+xxU for case-maintaining codes and u+xxu for downcased sequences
  minor, trial, use different designators for different lowercase/uppercase differences