Was looking a bit janky with the style changes.

Just sort of winging it.

For #1306.

If you want to use the last visited directory you should omit the
directory from the command line.

Fixes #1132.

Instead of the first.

- 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

Might fix #1181, although not for the reasons I initially
thought (because the URLs are resolved from the manifest path, not the
path of the current page). This should ensure that the URLs used by the
manifest are always correct regardless of the manifest's path.

Also add a way to force a check.

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

Otherwise there is risk of an infinite loop through the iframe where the
fallback keeps loading the root HTML which itself has an iframe...

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