* Prooftree support: fix problem with successive proofs
  (try example.ml with tree turned on, gives exn in Prooftree)

* Prooftree: fix evar support so it works
  Need patch for proof tree program and (maybe) modification of 
  output

* PG: add patch for background startup (needs testing)

* Integrate Tactic recording/proof refactoring (e.g. menu option)