Add PCB interface

this incorporates some of @chintal's layers.py changes
PCB.from_directory() simplifies loading of multiple gerbers
the PCB() class should be pretty helpful going forward...

the context classes could use some cleaning up, although I'd like to wait until the freecad stuff gets merged, that way we can try to refactor the context base to support more use cases

1 files changed, 0 insertions, 0 deletions

diff --git a/examples/pcb_bottom.png b/examples/pcb_bottom.png
new file mode 100644
index 0000000..1e8c369
--- /dev/null
+++ b/examples/pcb_bottom.png