Also fixes a bug with an empty room settings window introduced in the
port.

Also fixes some resize issues with stupid workarounds to our resize
logic. This really needs to be cleaned up at some point!

This fixes some weirdness on some platforms, where Qt.openUrlExternally
does weird stuff.

Limiting improves readability on wide monitors.

The immediate update of the settings is done by just exposing settings
as properties and then setting the settings as a context property.