tls support

o mongoc_stream_tls integration - takes a mongoc_stream and does ssl
  over it
o mongoc-ssl - handles a bunch of interesting ssl features
  o CRL
  o common name verification
  o password protected pem's
  o rfc 6125 hostname verification
tests: allow mock server to set wire version and run in thread.

This will allow us to use the server from test code for basic things.
If you want to specify a handler, you can even reply to your requests
so that you can verify the response parsing.
tests: test minWireVersion and maxWireVersion during connect process.
tests: use / in regex test to verify there is no weirdness.
tests: check the negotiated wire-version for expected failure mode.
tests: only sleep 5000 microseconds while we wait for thread to spin up.
added readme boiler plate support/bugs/security

Adding in MongoDB standard:
o Support / Feedback
o Bugs / Feature Requests
o Security Vulnerabilities
tls code review feedback integration

Addressing a bunch of little stuff (typos, style, etc)
Merge branch 'tls'