Scheduler : Schedule the call, precompute the
buffer in advance.

if the extension or the format is not recognised

- everything is converted to the new shiny way of doing things.
  Well, everything except Gappa, which seems very unifinished anyway,
  and Encoding_instantiate, which is too complex and would like to 
  update it with François.

Also, I commented a little piece of exception reporting in manager/,
will see it with Claude.

THIS IS STILL A WORK IN PROGRESS!
Please inform me about any bugs, ugly APIs, and proposed corrections.

All the non-implemented things, mentioned in the previous commit
message are still in the TODO list and will be done soon.

completion : complete theories and goals

constructor parameters : mainly useful for records, see 
examples/programs/vacid_0_sparse_array

registered formats: simplification: no more parse_only function, but boolean optional argument instead

If some goals are specified they are treated in the order of
apparition on the command line. If no goals are specified on the
command line, they are treated in the same order than they appear in
the theory.

simplify_trivial_quantifier va moins sous les triggers (il peut encore remplacer dessous mais pas y trouver d'égalité)