Create toggle button to allow invalid certificates.

[geoph9]

See #52 .

The idea is to add a toggle button (probably right below the panel icon option in the preferences) that will allow users to accept invalid tls certificates.

#52 contains the new _constructMessage function in utils.js. An addition to that would be that the user should also be warned (e.g. a red text would appear underneath that option in the preferences).

As for the implementation, there should be a global option allow-invalid-certificates in the app's configuration (and also in settings.js). Every time send_request (and _constructMessage) is called, this option will be read, and if true the accept-certificate handler will return true.

[thiyagarajan17]

please assign the issue.. would love to work on it!

[geoph9]

Thanks for offering!