use configurable font sizes for default button and ToggleButton
FlatButton's font size should equal content font size
consistent window title font size
ListViewScrollViewerStyle doesn't work
better MetroGridViewScrollViewerStyle
Merge pull request #743 from thoemmi/StyledFontSizes2

use configurable font sizes in styles
set FlatButtonFontSize to 14

looks much better than 12
change theme only if needed
Flyouts fade in/out.
Flyout's animation is faster.
Made one flyout wider.
Initial documentation of several controls.
fix stroke of MetroCircleButtonFocusVisual
extract SimpleCommand
minor change to theme/accent color menus
Finishing up the first pass on documentation.
Documented Accent, Theme and ThemeManager.
Merge pull request #748 from Amrykid/amry-documentation-r1

Code Documentation
minor changes to Scrollbars

cose cleanup and set VerticalScrollBarButtonHeightKey to 50
fix TextBox ScrollBar issue

- if a TextBox becomes multiline and it was resized, the ScrollBar goes
away
- introduce ButtonWidth to set the TextBox, ComboBox buttons manually
(default is 22, 24)