Twilight: Lighten background to compensate for gamma change in 10.6.
Twilight: Add background to code blocks in markup.
Twilight: Reduce border contrast and increase warmth of gutter.
Twilight: Ensure doctype tags get fully grayed out.
Twilight: Match diff index line style to header style.
Colorize Ruby symbols differently when used as hash key.
Fix coloring for ruby hash keys.
Highlight merge conflict markers.