Forked from AyushWheel (https://github.com/ayushhgoyal/AyushWheel) which is in turn copied from Android Wheel (https://code.google.com/p/android-wheel)
Changes:
- background customization (see res/values/attrs.xml)
- some fixes for potential memory leaks
- Gradle build configuration (see gradle.properties.example for build settings)
- cleanup