Fix issue 1051

This PR fixes issue #1051 by providing a better interface to input entry using a `CardWheelHorizontalView` widget.
The `CardWheelHorizontalView` widget behaves like a [`NumberPicker`](https://developer.android.com/reference/android/widget/NumberPicker.html) or a [`TimePicker`](https://developer.android.com/reference/android/widget/TimePicker.html) but horizontally instead of vertically.
For example, you can **swipe right/left** to quickly change values, **tap on the center value** to edit with a keyboard.

![widget_in_takeoff_mission_detail](https://cloud.githubusercontent.com/assets/914968/4252968/6f567dac-3a9a-11e4-8593-e79bfb738e2e.png)