TrianglesUseFore patch.

[Malcolm Still]

Hello Devs,

I hope you're all keeping well.  I thought it was about time that I gave something
back to FVWM, and the FVWM community, so this patch is dedicated in their
honour.

This patch allows users to use their menu foreground colour for
submenu triangles, by using the new MenuStyle keyword "TrianglesUseFore",
e.g.:

MenuStyle * TrianglesSolid, TrianglesUseFore

I've uploaded the patch to my webspace at:
http://rv.sdf-eu.org/trianglesusefore.diff

Obligatory screenshots, first without TrianglesUseFore:
http://rv.sdf-eu.org/withoutTrianglesUseFore.png

and with TrianglesUseFore enabled:
http://rv.sdf-eu.org/TrianglesUseFore.png

Thanks,
Malcolm "rhinovirus" Still