Add scaffold to run the ruby/openssl regression tests

Add scaffold to run the ruby/openssl regression tests

This test depends on the ruby/ruby-openssl-tests port that bundles the
sources and tests of the Ruby OpenSSL gem below /usr/local. The Makefile
compiles the openssl.so shared object below obj/ that provides Ruby
bindings for the OpenSSL API. Once this is built, the regression tests are
run.

There are currently 4 failing tests, all related to the new verifier.
At least one libssl bug is hidden behind a pend. All this will hopefully be
fixed during this release cycle.

This adds a decent amount of test coverage without being overly expensive.
This way, regressions should be spotted during development so jeremy will
no longer have to chase and work around them.

Joint work with jeremy, positive feedback from bcook and jsing.