Add android-ColorPickerPreference library

https://github.com/attenzione/android-ColorPickerPreference
Implement custom Hover notification colors

- Ability to set a custom notification background color
- Ability to set a custom title color
- Ability to set a custom text color
- Ability to set a custom left notification image color
- Ability to set a custom image background transparency
Fix default value of "Natural timeout"
Fix default notification text color in notification drawer

This color is set when the notification is sent from Hover to
notification drawer. An approx value was set.
Correct value is "#FFAAAAAA".
Bump to version 1.3