cpp: Add pkgconfig file for gpgmepp
* configure.ac: Add substitutions GPGMEPP_PKGCONFIG_LIBS, GPGMEPP_PKGCONFIG_CFLAGS, GPGMEPP_PKGCONFIG_HOST. Apply them. Configure gpgmepp.pc file. * lang/cpp/src/Makefile.am (pkgconfigdir, pkgconfig_DATA): New. (EXTRA_DIST): Add gpgmepp.pc.in. * lang/cpp/src/gpgmepp.pc.in: New.
This pkgconfig file will be used, at least temporarily, by qgpgme
to find gpgmepp, but it's also useful in general for projects that
don't use cmake.
- GnuPG-bug-id: T7262