Change session serialization so that element ordering no longer depends on hash values but on actual values.

Move the Fset.nth function into its own theory, as it causes smt provers to fail on queens.mlw and bellman_ford.mlw.

Fix the naming of the symmetric conjunction and document the splitting behavior of the asymmetric disjunction.

Fix some documentation typos. Add an empty line at the end of replayer_macros.tex to work around a bug in hevea's lstlisting implementation.

Use the actual html generated by why3session rather than an image for the html version of the documentation.

Do not update the proof duration if it changed by less than 10% or 0.1s, so as to avoid diff noise in session files.

The only significant difference between these functions is that the first
one is calling a callback function at each step, while the second one is
generating a report at the end. Any other differences are likely to be
actual bugs, which hopefully are now fixed. Now both functions call a
third one, which accepts callbacks that encompass all the previous
features.

Disclaimer: the code is ugly.

allows to show the warnings in the nightly bench