Encoding_instantiate keeps the type of the green part complexe.
Encoding_simple2 (bad name) replaces the complexe types by constants.

One day we can add a better comprehesion of (int,int) array for instance
 inside encoding_simple2 or inside the printers.

encoding_enumeration add projection for enumerated type. Seems to work (on valid and not valid goal) for simplify, spass, eprover

see examples/programs/sorted_list.mlw with eprover, spass, simplify!!

encoding_enumeration must be used with encoding_decorate and encoding_instantiate if an enumeration type is kept.

with a different logic of splitting in premises - to discuss.
Its main advantage is providing two transformations instead of 6.

- 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.

installation (work in progress, currently for developers only); why.conf is also searched for in the installation path (Config.why_libdir); in why.conf, theories and drivers filenames are relative to why.conf dirname (when relative)

now ocamlgraph can be used properly in hypothesis_selection

programs: the type-checker is back and the bug in vacid_0_sparse_array is now fixed; make bench is back

programs: complete rewrite of the type-checker in progress (in particular, types dterm and dfmla have been moved to Denv, together with some functions); make does not compile whyml anymore; make bench will stop at the first program test; with my apologies if I messed up somewhere...

bench : ajout d'un bench pour tester tous les provers sur des buts triviaux. Cela peut permettre de détecter un mauvais driver ou printer.

began implementing dynamic dependency graph in hypothesis_selection.ml