[Tor-BSD] Building Tor 0.2.7.x on OpenBSD

[Carlin Bingham]

I got 0.2.7.2-alpha to build with libevent2 and without bufferevents, by
setting the TOR_LIBEVENT_LIBS from attila's patch outside the
bufferevent conditional.

OpenBSD 5.7-stable amd64
Tor v0.2.7.2-alpha (git-36c0ae6f7834af16) running on OpenBSD with
Libevent 2.0.22-stable, OpenSSL LibreSSL 2.1 and Zlib 1.2.3.

Have been running it for almost 24 hours now with no problems.

--
Carlin