`State_selection` has its signature embedded into signature `S`, shared
with submodule `Static`, marked as deprecated since 2012. If #1103 is
fixed, we can revert this commit.

With the current checks, indexing `M.s` where `s` is in fact
`include`d in `M`'s signature can't be done with
`\scodeidx{M}{s}`: you can only refer to `\codeidx{M}` and
`\scodeidx{I}{s}` where `I` is the module where `s` actually appears.

[doc] Remove references to FRAMAC_LIBDIR in tutorial as it is no more needed (and source of errors).

- Fix Value/Value#5
- Fix Value/Value#14

Some case studies (e.g. dyad) use some ugly casts from fd_set_t which lead
to the analysis stopping too early.
Changing the representation of fd_set_t should also help it better conform to
the standard (since a fd_set_t should be able to hold FD_SETSIZE elements).

[Ptests] preserve LOG after STDOPT directive

See merge request frama-c/frama-c!2073

This is absolutely not a sneaky attempt to relaunch a build (now that OCI seems
in better shape) pushing a nearly empty commit.