demo syntax and using dump_demos to compare to ML

[Ben Abbott]

Rik,

I noticed you replaced the "..." line continuation with "\" in the demos.

Unfortunately, this breaks the "dump_demos" script Soren wrote to compare the 
gnuplot and fltk toolkits with Matlab (breaks the ability to run the demos 
using Matlab).

There may be some other changes the cause problems for using dump_demos to 
produce plots, via Matlab, as well.

Maybe it is a good idea to commit dump_demos.m and its companion html_compare.m 
and add the necessary parts to configure ?

That way more of the developers will be aware these scripts are used to look 
over the demo results, and that the plot demos need to avoid some Octave only 
syntax to allow plots to be produces using Matlab.

Thoughts ?

Ben