When a black-box item requests a specific footprint, we need to
read a file (<footprint>.fp) that contains the actual details
about that footprint. Support parse of that file and use the
loaded Element to generate the footprint for the item.
On Ubunto 10.10 (32 bit) tgt-pcb would not build because there were
include file issues. This patch fixes those and uses the C++ include
version where appropriate.
The main .pcb file contains elements, and basic PCB status.
Write out a .pcb file with stub Elements for each of the devices
in the design.
Rearrange the way the files are reported to the code generator
so that we can sensibly express where the output files are.