Feature request: forvec with an initial point

[Olivier Ramare <Olivier.Ramare@math.univ-lille1.fr>]

Dear all,

 When computations are aborted in the middle
of a forvec, it would be extremely interesting to
be able to start them again from where they
stopped.
 I guess it is not so difficult to implement,
though it will force the third argument of
forvec to be present.
 Cheers!
 Amities,
               Olivier