Zebra-color the divelist

Zebra-color the divelist

..as suggested by Nathan:

  "I also wanted to "zebra" color the divelist by setting the rules-hint
   to TRUE.  but I noticed it was already set explicitly to FALSE (even
   if this is the default).

   If this is just an accidental copy paste from some tutorial you can
   experiment (set it to TRUE) and see what you like most."

It was indeed just copy-paste from some tutorial, and the zebra-coloring
does look nicer, doesn't it?

Suggested-by: Nathan Samson <nathansamson@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>