Add environment option for secure local website

[G-Ambatte]

This PR adds support for the NODE_ENV environment variable to be set to local.secure. This option, when combined with a hostname configuration item, creates a webserver that serves pages secured with certificates configured for the hostname.

At this point in time, this is completely experimental and only of limited use in local installations. It has NOT been thoroughly tested, so some Homebrewery features may not work correctly with this environment setting.