Replace "Show NaN" option with "Show bogus".  Bogus values include
infinities, in addition to NaN.

Don't blend the bogus warning color with other warning colors, when
a pixel has both a bogus component, and a shadow/highlight
component.  The bogus warning always takes precedence.

Rename "Include alpha" option to "Include alpha component".

Remove "Opaque" option.  Warnings are now always opaue, even for
non-opaque pixels.

Add "Include transparent pixels" option, which controls whether
fully-transparent pixels are included in the warning.  A fully
transparent pixel is a pixel whose alpha component is less-than or
equal-to zero (note that this doesn't include a NaN alpha
component.)