uix:ColorPicker space effecient interface and add missing Documentation
uix:ColorPicker Move Color Bar to top, center sliders and add padding to
colorwheel(hopefully no more black dots).
uix:ColorPicker fix private Class names
uix: color picker add `font_size` used to set the font size of the
TextInput and the Labels inside ColorPicker. Add a example
`examples/widgets/colorpicker.py` for showcasing ColorPicker.
uix:ColorPicker change `label_color` to `foreground_color` for
consistency with other widgets; fix docs.
Merge pull request #1159 from kivy/color_picker

uix:ColorPicker space effecient interface and add missing Documentation