no need anymore to esplicitelly set $colored on button drawind function
define colors in one place

- DRY and clear when colors differ between light/dark
Added $noshadow to button drawing function to not draw the bottom hilight.
Fixed the vertical spinbutton superfluous outsets and backdrop insensitive
state.
add back bottom hilight to vertical switch
Removed _ prefix from calculated color names.
Fixed window close button transition.
Used a flat gradient istead of background color on insensitive entries.
remove trailing spaces
make some ifs more legible
indentation fix
one more legibility @if fix
Treeview headers
column-headers jumping around
Menus
entry: less brutal focused state
button: edge highlight tweak
button: add comment on the highlight
frames: avoid double frame
menu: whitespace separators
make focus-ring visible again.
Transparent outsets istead of removing for nicer transitions.
Replaced some @ifs with if() syntax.
generic separators