Detect all Trackers, not just those assigned to roles

[kitlith]

Kinda rewrote-ish a good portion of the feeder app in the process. whoops?

Current methodology is as follows:

• Try to detect all trackers by index, with role NONE.
• Try to detect all trackers through action system, with their respective roles.
• If pose NONE, put the tracker into a waiting state. On timeout, we notify the server of the tracker with role NONE.
• otherwise we notify the server immediately.

This supports updating the role of a tracker so long as the role doesn't change to NONE. I'm not changing that right now. should probably list that as a known issue in the README I guess.

[kitlith]

Works for both me and Erimel, so I'm pulling the trigger and making a release.