with the task pretty printed, it reduce the set of axioms to a minimal
 set of declaration which still prove the goal and pretty print it.

Currently it does the bisection on the goal already prepared for the prover

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