Add parameters for optionally correct small wrong ENGINE DC errors.
  hdc_fix_lr
    Historically, in the ENGINE, if a hit is used in multiple
    space points/stubs, the left/right assignment for that hit, which
    is later used in track fitting, is that assigned for the last stub
    encountered with that hit.  Properly, the left right assignment
    should be allowed to be different in different space points.  If
    this parameter is set to zero (e.g. in hcana.param), then the
    ENGINE behavior is used.  For new analyses, it should be set to one.
    (Which is the default)
  hdc_fix_propcorr
    When a hit gets put into a stub, the distance of the hit from the
    discriminator can then be estimated.  In the engine, a correction to
    the drift time (and thus drift distance) is applied.  However, if
    that hit ends up in another stub, the correction will get applied again,
    resulting in a over correction.  Setting this flag to 1 will give that
    hit a different corection for each stub that it is in.
A bit more implementation of ENGINE compatibility parameters.