RFR: 8155928: Remove hardcoded port numbers from httpclient/Security.java test

[Michael McMahon]

Some tests with hardcoded port numbers were included in the initial http 
tests.

The fix uses a driver to allocate a free port and pass it into the existing
security test through a system property.
http://cr.openjdk.java.net/~michaelm/8155928/webrev.1/index.html

Thanks,
Michael