All board config macros now begin with MICROPY_HW_.

Renamed PYBv10 to PYBV10, since macros should be all uppercase.

Made SDCARD_DETECT configurable in mpconfigport.h, so that the SD
detect pin can be easily configured.

Added support for the ADC channels and mappings to make_pins.py

I'm not sure if the hal properly deals with the channel 16/18 differences
between the 40x and 42x. It seems to deal with it partially. This particular
aspect will need testing on a 42x or 43x.

Tweaked a couple of the USB files to compile if neither dev nor host was defined.
Tested on netduiono plus 2 and stm32f4discovery boards

Enumerates CDC device over USB, but doesn't transmit/receive yet.

This compiles and links, but hasn't been tested on a board
yet and even if it was run, it doesn't currently do anything.