Good thing, there is no more any version-specific Coq realizations

forgot to add .mli file to commit

Change-Id: I28d89aa1f85ff5a3e19a495babcdd707545607f4

We set the error mode in the why3 server. This has two effects:
- disable pop-ups in case of crashes of why3server;
- inherit this setting to all spawned prover processes.

* server-win.c
(main): call SetErrorMode

Change-Id: I93862d51aebe1d4639ab1d463c08366f79375a7a

The extmap.ml file was taken (and extended) from ocaml 3.12 and has not
been updated since. Since then, ocaml map.ml has evolved and contains
some space optimizations.

The commit contains more changes than strictly needed. The objective is
to be as close as possible to map.ml from ocaml 4.04. After this patch,
the 'diff' wrt. map.ml  contains almost exclusively additions, and no
other changes.

Change-Id: I3e31f6068562e5e1c48f8426efc9ce4e2f5b6010

TODO: make this a configurable option