- Define set with create (and constrained a benign mistake on axioms)
- s/FloatMatrix/Matrix

to handle non-square matrices

- Call_provers.parse_prover_run does not attempt fixing answer anymore,
  except in the case where the answer is HighFailure and time is close
  to time limit (which is considered as Timeout)

- Session_scheduler.fuzzy_proof_time is now more liberal, accepts
  that two answers Unknown or Timeout of OutOfMemory with less than
  10% difference in time are equivalent, and thus should not be
  reported as a significant change

Adding "I don't know" as a correct keyword for provers return (inside
counterexamples).
Updating scripts because of move from hoare_logic to WP_revisited.

* src/driver/parse_smtv2_model.ml
(parse): Adding I dont know as a keyword.

* bench/bench
Changing to WP_revisited.

* examples/bench.sh
Changing to WP_revisited.

* examples/regtests.sh
Changing to WP_revisited.

simplifies the gallery update

When Why3 is run on a file where some theories have been suppressed, it
will delete the corresponding theories from the session file.  We now
add an option keep_unmatched_theories to Session.update_session, which
keeps all theories. In this commit, this option is always disabled.

This is useful for SPARK, which sometimes only generates part of the
Why3 file for efficiency reasons, but doesn't want the session file to
be damaged because of that.

* session.ml
(import_theory)
(import_goal)
(import_proof_attempt)
(import_transf): new functions to copy a session tree from an old
  session file
(merge_file): keep old theories when keep_unmatched_theories is true
* session_scheduler.ml
(update_session): pass keep_unmatched_theories
* why3session_lib.ml
(read_update_session): pass keep_unmatched_theories