add MetroLabel style
improve flyout style
+ improve/update style for left and right flyouts
+ fix foreground bug (force showing WhiteBrush color)
update flyouts demo
+ add more examples for right and left flyouts
add FlyoutWhiteBrush for dark and light accents
improve some controls for flyout usage
+ change foreground of checkbox, label, radiobutton and textblock to FlyoutWhiteColor / FlyoutWhiteBrush
Merge branch 'flyouts' of git://github.com/punker76/MahApps.Metro into punker76-flyouts