Enhance the glass effect on title bar

themes/default/README

themes/default/close-pressed.png

themes/default/hide-pressed.png

themes/default/maximize-pressed.png

themes/default/maximize-toggled-pressed.png

themes/default/menu-pressed.png

themes/default/shade-pressed.png

themes/default/shade-toggled-pressed.png

themes/default/stick-pressed.png

themes/default/stick-toggled-pressed.png

themes/default/title-1-active.png

themes/default/title-1-inactive.png

themes/default/title-2-active.png

themes/default/title-2-inactive.png

themes/default/title-3-active.png

themes/default/title-3-inactive.png

themes/default/title-4-active.png

themes/default/title-4-inactive.png

themes/default/title-5-active.png

themes/default/title-5-inactive.png