- use `CheckBox.icon.selectedBackground` as base color for derived "selected" colors
- use derived colors for `CheckBox.icon[filled].selectedHoverBackground` and `CheckBox.icon[filled].selectedPressedBackground`
- removed unnecessary `CheckBox.icon.selectedFocusedBorderColor`from FlatDarkLaf.properties
- added missing keys to FlatLafUIKeys.txt
(preparation for #176)
- changed default color to bluish
- made track thinner (2px, was 3px)
- made thumb larger (12px, was 11px)
- added thumb outline focus indicator (4px wide)
- slider component height increased from 11px to 20px
- support painting thumb border
- support different colors for thumb background and colored track
- updated with latest changes from FlatSliderUI
- use static FlatSliderUI methods for thumb painting
- hover/pressed feedback on single thumb
- hover/pressed feedback on middle track and both thumbs
- added JSlider components to FlatRangeSliderTest for easier testing/comparing
- use rounded rectangles for buttons in tab area
- "pressed" background for buttons in tab area
- fill background of buttons in tab area
- use derived colors for hover and pressed
- fixed missing arrow in "more tabs" button at larger scaling
- made tabs separator color lighter in dark themes so that it is easier to recognize the tabbed pane
- added top and bottom tab insets to avoid that large tab icons are painted over active tab underline
developed to find out whether it is possible to detect Windows screen scaling and text scaling factors in Java 8, which seems to be possible by using "win.defaultGUI.font" desktop property
issue #175
