From DJB: "For correctness, ./test has to be run on the installation
machine, not on the machine preparing a binary package." (Also: "The
issues are explained in Section 8 of
https://pqcrypto.eu.org/deliverables/d2.4.pdf.")

For this to work, we install the source tree (with built objects) to
${PREFIX}/share/djbsort. Then we run tests, install to ${PREFIX}/include
and ${PREFIX}/lib, and check the installed files against pseudo-PLIST.

This means pkg_add(1) will fail if no C compiler is present, which is
unusual behavior for pkg_add but perhaps not entirely unreasonable for a
C library.

Bump PKGREVISION.

(schmonz)