Revision 38572

  Add new derivation of TList (TProofOutputList) to be used on the PROOF client to filter out
  PROOF internal objects when displaying or printing the list. By default objects was names start
  with 'PROOF_' are not shown. The presence of a non empty missing file list is notified.
  To list or print the full list the string "ALL" must be passed before any other ls() or print()
  options, e.g.

    root [] gProof->GetOutputList()->ls("<opt>")

  show only user objects (i.e. apply name filtering); and

    root [] gProof->GetOutputList()->ls("ALL<opt>")

  show all objects according to '<opt>' (i.e. no additional filter applied).