- Porting of all the code to the new DTD format (with, among others, explicit

- Porting of all the code to the new DTD format (with, among others, explicit
  named substitutions)
- Porting to the new version of Pxp
- Porting of the cicReductionMachine code (that was abandoned for a while)
- Removal of all the cooking machinery
- Removal of the optimization (memoization) of the computation of recursive
  arguments of constructors. Required to implement the next point. The actual
  performance loss is minimal.
- First prototype of an environment with trusting abilities.

Notes: unification is still untested and probably wrong w.r.t. explicit
 name substitutions.