SSL certificate verification PYTHON-466
Standardize tests' handling of DB_IP and DB_PORT, fix PYTHON-475
Fix up SSL tests.

Tests shouldn't fail if python doesn't have an ssl
module. Other changes include:

- Document how to test all this (i.e. how to start the server for
  these tests to run)
- Don't do requirements testing in setUp since it's run before every
  method.
- Move the "no ssl module" test into it's own test class
Clean up match_hostname import