Adds Menus brushes.
Adds MenuStyle, MenuItemStile to the MainWindow.xaml
Changes Checkmark geometry.
Adds trigger for Glyph.
Changes Glyphs margin, height, width.
Adds SubMenuRepeatButtonBrush, SubMenuHoverRepeatButtonBrush to the Styles.xaml
Changes Menus RepeatButton style.
Adds DownArrowGeometry, UpArrowGeometry to the Styles.
Adds DisabledMenuForeground to the Styles.
Adds image resource to the project.
Adds MenuSeparatorStyle to the MainWindow. Adds MenuSeparatorBrush to the Stiles.xaml
Separates common colors.
Moves Menu style to the Styles.xaml. Separates Geometries from all controls in the Styles.xaml.
Changes separator style.
Changes DisabledButtonBackground color. Renames TextBoxDisabledBackground  brush to  ComboBoxDisabledBackground.
Adds TextBoxDisabledBackground Brush.
Fixes TabControl disable state.
Fixes TreeView disable state.
Removes TreeView border.
Removes redundant code.