Replace all objects by new ones from the current libraries
shipped by Kicad.
This causes a slightly different OSHW (Opensource Hardware)
logo to be used in the PCB.
To maintain schematic parity, all mechanical objects on the
PCB (mounting holes and OSHW logo) have their schematic
counterparts now.
Symbols had to be recreated because they were not part of
original dataset.
Footprint library now needs to end in .pretty
Still many DRC warnings, but the basic result ought to be
the same as before now.
