More colours :sparkles:

- Add more colors (from http://developer.android.com/design/style/color.html)
- Split user defined colors and default colors
- Ordered color list (user defined colors first)
- Simplify the "Add new colour" dialog
- Colours are validated by Color.parseColor(String) and therefore more flexible
- FloatLabelLayout from @chrisbanes (https://gist.github.com/chrisbanes/11247418)
- Delete user defined colours
It was a mistake.