Fixes #27. Set the hoveredIndex on TabControl to -1 when the OnMouseOut event triggers.
Added DisplayFormat to SpinBox.
Allows SpinBox to display Standard Numeric Formats (currency, exponential, percentage etc) instead of just the Number format.
Merge pull request #28 from behindcurtain3/master

Fixes #27. Set the hoveredIndex on TabControl to -1 when the OnMouseOut event triggers.