Console UI should not depend on core modules

[Cas]

While looking at a PR removing dependency on core.rpcserver in Web UI I wondered if any other UI components also had core module dependency and found:

from deluge.core.preferencesmanager import DEFAULT_PREFS

​https://github.com/deluge-torrent/deluge/blob/develop/deluge/ui/console/widgets/statusbars.py#L14

This means that it is harder to package console UI without including the core code so should be replaced

[DjLegolas]

To change this, we should have a way to get the default values from preferencesmanager.
There are 2 ways that I can think of right now:

1. Move the defaults to a different file, outside of core.preferencesmanager.
2. Add an exported function that will return it.

I have a feeling that there might be a better solution for this.

[Cas]

Since it's only used for the unchanging daemon_port I would just hard-code it to 58846.

If you wanted a better change we would set a common DEFAULT_DAEMON_PORT constant to be used throughout the code but we don't really gain anything.