Hello,
As discussed in the freetype/fontconfig pkgconfig thread, here's a combined patch implementing installation of VDR's headers and generating a pkgconfig *.pc file.
This patch is mostly just a discussion draft - I haven't tried installing the headers and the pkgconfig file isn't installed yet by any "make install*" (mostly because very ironically, there's no way to query pkg-config for its default search path, which is something I've intended to report a bug about since a long time ago, but failed so far - maybe I'll do it right now :)).
Also, I don't know if all *.h are actually something that should be installed by "install-headers", but since they're all available in the current setup for plugins to use too, I suppose weeding through them is an orthogonal task to this patch if needed in the first place (and maybe better discussed in the "RFC: Makefile ravamp" [sic] thread from Sat 8th Mar).