This commit also introduces a new shared-bindings directory which is used to store the common Python -> C binding code. By having a shared directory we can ensure that the Python API across ports is the same. Each port will have a corresponding common-hal directory which provides definitions for the C api used in the shared-bindings code. That way the compiler can enforce the C api.
To migrate to this new shared API create a common-hal directory within your port and change the Makefile to compile both the shared-bindings and common-hal files. See atmel-samd/Makefile SRC_BINDINGS for an example.
All of the code was there except the linker was failing to clear the bss section because I added too many .zeros. The should have only been the exported globals that start with _ like _szero = .. Fixing that and turn on the usb transmit fixed everything.
Everything works fine without USB being plugged in but faults (I think) when USB is plugged in. This is switched away from the USB code from the bootloader onto the USB code thats generated by Atmel Studio using the high level classes from ASF.
