Seems AC_PATH_GENERIC() wasn't present somewhere, then I'm adding the
AM_PATH_LIBGCRYPT() provided by libcrypt (I need to include it in m4/
otherwise it will fail for people doing ./autogen.sh without libgcrypt
installed).
It works on my machine, but `libgcrypt-config --libs` output is just
"-lgcrypt -lgpg-error", including no -L.
SVN revision: 82939