Done

0. After F2c'ing, and declaring things, I now get the compiler warnings

  fdcore.c: In function `pqopt_':
  fdcore.c:561: warning: passing arg 18 of `lmder1_' from incompatible pointer type
  fdcore.c:573: warning: passing arg 18 of `lmder1_' from incompatible pointer type
  fdcore.c:583: warning: passing arg 18 of `lmder1_' from incompatible pointer type

  and indeed, the argument passed is   &w[woptfd_1.ipvt]
  but this is internally treated as  *integer*  '*ipvt'

  ===> reason for occasional seg.faults !?

  fracdf() -> dopt() -> pqopt()
	   really should pass a double w[]  PLUS an  int iw[]

  ___ DONE, 2004-10-xx (MM) ___

1. Estimation now produces a class with print(), summary(), coef(),
   logLik() and vcov() methods

1b. fracdiff.sim() improved, now allowing non-Gaussian innovations.

2. Translate to C,
  ___ DONE, 2004-09-18 (MM) ___

5. Jan de Leeuw cannot link things on Mac OSX using "flat namespaces"
   (because the Common Blocks look like having multiple definitions)
   --> start cleaning up common blocks in general.  2005-06-29
   mostly finished; at least CRAN-checks are fine now.