Fix #2031 - Rewrite cipher check to reduce TLS conns

This drops the direct use of sslyze's cipher checks,
and switches to a custom version, using many of sslyze's
APIs, that tests more ciphers at the same time.
This should dramatically reduce connection count.

Paralellism for web and mail has been reworked somewhat
too, as we don't use the sslyze scheduler as much now.

Currently built on top of #2083.

Author: mxsasha