Fixed - Toggle button has the same look when pressed both checked and unchecked

Fixed - Split button should only have a border around the part you are not hovered over
and the border should be the same color as the part being hovered over.

Fixed - Split button when left side is pressed the toggle button look should not change
Note: the border should still be around the toggle button during this press

Fixed - MenuButton should not stay dark after the popup opens
It should go to the highlight color
Merge pull request #8 from kiangtengl/ribbon-menu-support

Ribbon Menu Split Button Fixes