Two different y-axes



> yaxis_secondary
> ytics_secondary
> 
> Or shorter, but not so "correct":
> 
> yaxis2
> ytics2.
> 


In current cvs version I added these new options to give some support
for the second y-axis:

y2range
y2tics
y2tics_rotate
y2tics_axis
right_axis

which should be changed to something like:

yrange_secondary
ytics_secondary
ytics_rotate_secondary
ytics_axis_secondary
yaxis_secondary

respectively.

I don't have any problems renaming them this way.


> 
> Maybe the addition to userpreamble can be automatically set when  
> yaxis_secondary = true?

Yes, I had also this in mind for the next commit.

Thanks for your comments.

-- 
Mario