[WO-421] Rework host authentication

Allow pinning of arbitrary hosts

Add socket.oncert(pem) callback to Chrome shim with the pem-encoded
certificate
user useSecureTransport instead of useSSL
added test cases and documentation
Add comments to TLS verification
Merge pull request #2 from whiteout-io/dev/WO-421

[WO-421] Rework host authentication