Poelli 1.0

1.0. Version of PoElli-Nucleo. 

It's still not perfect, but unless prototypes show some showstopper bugs first production round should be based on this design.

Future improvement:
- C35 should be moved between ferrites and zener D12 for better transient protection and noise suppression
- "NC"-text on pin headers should have a bir more clearance from pin headers
- Ethernet connector footprint should have bigger holes for signal lines
- UVLO should have separate treshold from locking pass transistor of outgoing 48 V
- Grounding scheme is a bit questionable, as DC/DC currents flow under signal transformer