[Foldit] Add abilty to suppress Quest to the Native popup.
If you include a guide structure in the puzzle, you automatically get
a "This protein's structure is known. See if you can match it!" popup.
There's the possiblility you may want to include a guide structure
without having that popup. (e.g. to provide a reference backbone in case
you don't want to move too far.)
This commit adds a puzzle_setup option `"quest_to_native"` which can be
set false to turn off the popup. The default if the option isn't given
is true, so existing puzzles should work as they have.
Intro/Education/Dojo puzzles should also be unaffected.