Adafruit-circuitpython-hid

* Correct struct format to correct signed-ness.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-hid`.

Read the [docs](http://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-hid`.

Read the [docs](http://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.

- Add `ConsumerControlCode.MUTE`.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-hid`.

Read the [docs](http://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.

Add `Keycode` names that correspond to Mac and Windows keyboard labels, for more obvious use without having to refer to the documentation.

- Add `Keycode.WINDOWS` and `Keycode.COMMAND` as aliases for `Keycode.GUI`.
- Add `Keycode.OPTION` as alias for `Keycode.ALT`.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-hid`.

Read the [docs](http://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.

- Added `setup.py`
- Added PyPI release info to `.travis.yml`
- Updated `requirements.txt`
- Added a more comprehensive `.gitignore`

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-hid`.

Read the [docs](http://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.

Consumer control and gamepad documentation was missing from `api.rst`.

To use in CircuitPython, download the .mpy file and copy it to the `lib` folder on the `CIRCUITPY` drive. Or, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

Read the [docs](https://circuitpython.readthedocs.io/projects/hid/en/latest/) for info on how to use it.