demo/plugin Makefile is not derivative of configure

[Daniel J S. <dan...@ie...>]

I've tried to build gnuplot in a directory other than the "src" 
directory but it failed because the demo/plugin/Makefile is missing from 
the "build" directory.  The reason is that demo/plugin/Makefile is in 
the repository and not generated from the ./prepare and ./configure 
build process.  If I use

../gnuplot/configure --with-qt --disable-plugins

gnuplot builds without problem.

Should I try fixing that?  Or is the change to a Makefile.in or 
Makefile.am.in obvious to someone else?

Thanks,

Dan