bring back gset

[Ethan Tira-Thompson]

Just my 2¢ on the gset -> __gnuplot_set__ -> obsolete transition: I  
disagree strongly.

My understanding from other postings is that octave aims to be Matlab  
compatible, but I see no reason to restrict everyone to Matlab's  
feature set.  I don't care about Matlab compatability, I want to be  
able to directly tweak my gnuplot output.  I understand others do want  
Matlab compatibility, but they can simply avoid using 'gset'.

Perhaps the better way to do this instead of writing off opportunities  
for innovation within octave, is to create an environment setting  
'MATLAB_STRICT' or some such, which if set, displays an error/warning  
if non-matlab commands are encountered, but if unset doesn't worry  
about it.

You could go a step further with this and use the setting as a matlab  
version number, so users could even track if they use a feature  
unavailable in the specific version of matlab of concern.

Thanks!
   -Ethan