Added an indication of which palette colors are being used.

-- The palette swatch will have a glyph to indicate it's the current
foreground/background color.
-- We print the color name beside the foreground/background color editor
fields.
Added a button to swap the fg/bg colors of a keycap.

Also:
-- fixed colors of text to go through same lightening process as keycap
-- fixed styles for right-aligned side-printed text.