Fix dark theme canvas glow
Remove the PLI left border from dark theme

was dashed, but looked very weird with dark’s round corners
Fix debated frame glow bug

Frames after a debated frame would keep their "debated" glow because of
a misinterpretation of the isDebated() function by
updateAllWithoutSliders(). isDebated() only checks the debated ratio and
must always be used in conjunction with isSpecial().

Added an explanatory comment to isSpecial().