[Kst] [Bug 144626] For fit plugins allow user to optionally supply x-vector for fit calculation

[Barth Netterfield]

The residuals have to be based on the original X,Y pairs, as it currently does 
(this is almost by definition).

But: The fit results can and should be evaluated on the new X vector.

On September 27, 2007, Andrew Walker wrote:
> ------- Additional Comments From arwalker sumusltd com  2007-09-27 20:40
> ------- I think my preference here would be to add an additional x-vector.
> The result and residual vectors would be provided basesd on the additional
> x-vector. In the case where the additional x-vector is the same as the base
> x-vector then the existing behaviour is returned. This would be the default
> behaviour. _______________________________________________