New performance counter [bs].

entry states.

triggering an error in this state.
This is about 10x faster for alphaCaml.mly. Still, alphaprolog.mly
does not go through.

Try to reach a pair (s', z) only if this pair causes an error.

The second analysis (backward search) replaces them.

Added a comment in [Coverage] about the use of
  [CompletedNatWitness] versus [BooleanWitness].

Maybe working (that remains to be confirmed), but too slow on real grammars.

for every nonterminal symbol.

This information is displayed at log level -lg 2.
Changed the display to not include the artificial start symbols.

of flat lists.

produce the same result as the old one.

no longer used.

are checked to produce the same results.

users.

place of the old ones (removed).

[Fix], instead of the old ad hoc mechanism. Unfinished.

plus a comment on compatibility with ocamlyacc
when there are end-of-stream conflicts.