Closes #1583

Closes #1502

This makes the code much more internally consistent (providers just
return payloads, include the proxy provider).

The cookie will be set for the proxy domain so it'll work for all of its
subdomains.

It'll be able to handle /proxy requests as well as subdomains.

This will be used for proxying ports.

- Add type to HTTP options.
- Fix certificate message always saying it was generated.
- Dedent output not directly related to the HTTP server.
- Remove unnecessary comma.

That way if they happen to conflict code-server doesn't crash.

For #1306.

Also make it a number.

Fixes #1312.

Just display the error message and exit. The stack trace isn't necessary
(since it's likely user error) and is potentially confusing.

- Add VS Code icon
- Trim dashboard to just display dedicated VS Code section
- Version was getting unset during build
- Add back nbin shim which I temporarily took out earlier
- Update tests for log level env var changes

Just a login form and a list of applications. No modals or anything like
that.

This is mostly for development where VS Code might not have finished
compiling yet.