This adds a `-wizard` CLI option to the Manager, which opens a webbrowser
and shows the First-Time Wizard to aid in configuration of Flamenco.
This is work in progress. The wizard is just one page, and doesn't save
anything yet to the configuration.
A wrapper for the generated `ApiClient` class tracks the number of running
queries. This makes it much simpler to show the "API calls pending" UI
element, regardless of which part of the webapp performs the queries.