Hub and power management

[aacuevas]

On last meeting (May 9th) we discussed how a "Hub meganode" don't necessarily must correspond 1:1 to a physical hub, but be more related to what the user expects of a given port or element group.

Following this principle, it makes sense to include the Link Control devices in the hub nodes representing remote hubs, this way, at initialization, the hub node would set the appropriate voltage to the link to support the actual plugged element, and can turn the port voltage down to 0 at stop.

This is desirable, as automates voltage settings, which are a problematic part of the current design, but introduces a new challenge: After powering up a port, a new reset would be needed to get the devices of that hub into the device map, before any settings can be written to them.

This means potentially several resets which, ideally, should be grouped together as one.