New Control: NumericUpDown family

[rabbitism]

1. This bunch of controls utilize only one template but supports type safe control for every built in C# primitive number types.
2. It supports Byte, SByte, Short, UShort, Int, UInt, Long, ULong, Float, Double, Decimal
3. Value is nullable but supports empty input fallback value.
4. When set AllowDrag = true, it supports dragging to change values. DoubleClick on textbox will enter edit mode, Esc or lost focus will exit edit mode.