* Track status pin use by user code separately so it can take over the pins and then give them back.
* Switch to hardware SPI for APA102 on Gemma and Trinket.
* Merge microcontroller/types.h into microcontroller/Pin.h to better match approach going forwards.
This was done to allow greatly granularity when deciding what functionality
is built into each board's build. For example, this way pulseio can be
omitted to allow for something else such as touchio.
The new sequence is as follows:
* Solid blue during the boot/settings script.
* Solid green during the main/code script.
* After main while waiting to enter repl or reset:
* Fading green once main is done successfully.
* On error produce a series of flashes:
* Long flash color of script.
* Long flash color of error:
* Green = IndentationError
* Cyan = SyntaxError
* White = NameError
* Orange = OSError
* Yellow = Other error
* Line number of the exception by digit. Number of flashes represents value.
* Thousands = White
* Hundreds = Blue
* Tens = Yellow
* Ones = Cyan
* Off for a period and then repeats.
At any point a write to the flash storage will flicker red.
Fixes#63
Docs are here: http://tannewt-micropython.readthedocs.io/en/microcontroller/
It differs from upstream's machine in the following ways:
* Python API is identical across ports due to code structure. (Lives in shared-bindings)
* Focuses on abstracting common functionality (AnalogIn) and not representing structure (ADC).
* Documentation lives with code making it easy to ensure they match.
* Pin is split into references (board.D13 and microcontroller.pin.PA17) and functionality (DigitalInOut).
* All nativeio classes claim underlying hardware resources when inited on construction, support Context Managers (aka with statements) and have deinit methods which release the claimed hardware.
* All constructors take pin references rather than peripheral ids. Its up to the implementation to find hardware or throw and exception.
