(PKGCONFIG_FILES, pkgconfigdir): New variables.

(DISTFILES): Added nettle.pc.in and hogweed.pc.in.
(nettle.pc, hogweed.pc): New targets (invoking config.status).
(install-pkgconfig, uninstall-pkgconfig): New targets.
(install-here): Depend on install-pkgconfig.
(uninstall-here): Depend on uninstall-pkgconfig.
(distclean-here): Delete nettle.pc and hogweed.pc.

Rev: nettle/ChangeLog:1.209
Rev: nettle/Makefile.in:1.37