#1645 "#define SMOOTH_BINS_OPTION" should be added to config.xxx

[Tatsuro MATSUOKA]

This was discussed in
http://gnuplot.10905.n7.nabble.com/random-dem-td19594.html

The change on
2015-06-26 Ethan A Merritt merritt@u.washington.edu

     configure.ac demo/bins.dem docs/gnuplot.doc src/gp_types.h
src/plot2d.c src/interpol.c src/interpol.h demo/random.dem:

New data filter "bins" sorts the original data into equal width bins
on x and then plots a single value per bin. The default number of bins
is controlled by `set samples`, but this can be changed by giving an
explicit number bins=N in the plot command.  The new feature is marked
EXPERIMENTAL in the documentation because we may decide to change the
syntax to "smooth bins" or "filter bins" or something else.

smooth bin was not effective on windows build

This happened because
#define SMOOTH_BINS_OPTION
was not added into config/config.(xxx) for non-configure build.

[Ethan Merritt]

I have moved the definition of SMOOTH_BINS_OPTION into plot2d.h

[Tatsuro MATSUOKA]

2015-07-03 Ethan A Merritt merritt@u.washington.edu

* configure.ac src/plot2d.h:  Move the definition of SMOOTH_BINS_OPTION
into plot2d.h, since configure.ac is not seen by the build system on
MSWin.

The change fix the issue. Thanks!