Help functions for plots

[courtiol]

?plot does not seem to work and yet plot from IsoriX masks both package:graphics and package:base.

[courtiol]

In fact now ?plot works in the sense that it does not mask the other plotting functions: R opens a menu to choose which help page to consult. Yet for IsoriX, it only list there the reexport help page and not the page that actually describes how to use plot.ISOFIT etc.