This uses a single default user in the config database, which is
auto-logged into the app when SERVER_MODE = False. In this mode we
also hide/remove user-related functions in the UI.
instead. Add support to the runtime to allow the user to specify the
Python path. This needs to be more automated for release, but will be
useful for debugging and development.
Upon startup, the runtime will attempt to locate pgAdmin4.py in a
number of different relative locations. Once found, it will execute
it in a new thread. The main window is then created and the brower's
initial page is set to the root of the CherryPy server. At present,
that's http://127.0.0.1:8080.