Classify all 14271 nonterminals by adding singletons and other metrics
9756 classified out of 14271, even if not counting v/h/s
Fix extraction of the Malton&Dahn C grammar
Classify 9791 out of 14344, with several tricks enforcing consistency
Merge branch 'master' of github.com:grammarware/slps
Reclassify 9792 of 14345 nonterminals, added preterminals of HATS ABS grammar