Log Message:
Update to 1.3.4:

Serf 1.3.4 [2014-02-08, from /tags/1.3.4, rxxxx]
  Fix issue #119: Endless loop during ssl tunnel setup with Negotiate authn
  Fix issue #123: Can't setup ssl tunnel which sends Connection close header
  Fix a race condition when initializing OpenSSL from multiple threads (r2263)
  Fix issue #138: Incorrect pkg-config file when GSSAPI isn't configured