Actually added mux_proto and vector_uint8

Added example_comms.py which gives a really bad example of comms with
PySerial. better python based code is on the way.
Merge branch 'dev' of https://github.com/cwoodall/nasa-mux-16ch-firmware.git into dev
Added stepping functionality to DAC7512 channel 2, can step between a
few hz to a about 5kHz.
Updated the readme file and main.c file to furthur document the new
settings.
Added toggling functionality and documented the registers
Merge pull request #1 from cwoodall/dev

Sent to BMC