Added hostapp program
Added text entry widget for connection port
Started backside sticker drawing
Made it easier to work on the sticker

There's now a proof target to create a printable sticker to test
on the chassis.
Added documentation for curper command
Fixed const data type argument for help command
Added functions to load and save the serial number
Added $setser command to set serial number.
Modified chassis sticker
Added some tests
New branch for working on plot interface
Switched to matplotlib for ui
Added todos for hostapp
Moved text around on sticker
Added stop key to user interface
Changed $curoff to take a uA argument
Modified current sample averaging to keep 2 extra bits
Added section describing calibration to howto
Added dummy connection to hostapp
Changed a TODO