the type alias "type unit = tuple0" goes into tasks and
therefore should be retrievable via Env

in three cases, we use a proof by an earlier version of Alt-Ergo
as a sample for bisection and then reprove it with other provers.

Also, moved all sessions in theories/ and modules/ to
tests/theory-sessions/. These sessions are not replayed
by nightly-builds and should not be distributed.
Please, do not run why3ide on the standard library files,
make separate files in examples/ using those theories, or
just realize them in Coq. Don't clobber the loadpath.

we really, really should implement blacklists in drivers

- recognize versioned executables
- mark old versions as old
- mark all Simplify versions old
    and I'd like to get rid of it completely

also, fix the evaluation order to left-to-right in e_binop.
Thanks to Johannes for the bug report.