Cvloop

- Adding annotation feature. Thanks AndreaSuckro .
- Adding conda-forge support.

- Updating README.rst to reflect that Python 3.5 is no longer supported.
- `__version__` is accessed without importing everything.

- Uses some defaults to find the paths for the cascades. The path can be accessed using `cvloop.OPENCV_CASCADE_PATH`.
- Including LICENSE in package distribution.

* The webcam no longer takes precedence over video files.

* Classes instead of functions to handle state.
* DrawHat feature (by JustinShenk)
* Video controls: Pause button + stop on figure closing.

* Animation with blits instead of draws.
* Matplotlib selects nbAgg if the backend is inline automatically
* Removing `%matplotlib notebook` from examples
* Updated documentation notebooks: removing `print_info`, as it is no longer supported.
* Added note about keeping a reference to the loop's return value