lambdadelta

- we changed the beta-reductum to make reduction a special case of
  extended reduction, the lenv refinement for native validity was
  updated accordingly
- we parked restricted reduction, substitution and lenv refinement for
  static type assignment
- active notations are now one per file and are included by nead: this
  avoids time-wasting recompilations when notations are added, removed,
  or changed
- Makefile: some speed up, uses new version of mac, handles auxiliary
  xoa files that can be included by need to avoid time-wasting
  recompilations when xoa objects are added
mac
- now outputs the pages count
probe
- minor bug fix: exceptions during file removal where not cought