Listen for HTTPS requests and generate SSL cert
Add 'listen 443 ssl' to local-nginx-example.conf-sample
Merge remote-tracking branch 'xteam/https-sites'
Make server private key generation quieter

With the way that Vagrant works when scrolling screens through, the private key generation ends up being a looooooong series of red dots. By storing the command as we issue it, we can provide a nice one or two line output as we go instead.

We'll apply this to other commands as well, this just happens to be the current longest offender.
Clean up some spacing for readability
Make the SSL cert signing a bit quieter as well

See changes from d7d1595 for explanation
Spacing and wording changes in provisioning output