Bugs corrected
* Now the -v option deals correctly with independent variable(s)
i.e. -f "a*z+b" -v z, or
-f "a*z+b" "b*q**alpha" -v z q
* For multiple fitting functions as in the line above,
a single figure is displayed with the plots
Add the following option
-w --weight: use the available data (3rd col or sigma) as weight only
-e --errbar: use the available data (3rd col or sigma) as errorbars