Disallowing unprivileged users from viewing poll results

Use case: a site wants to collect info from users without users being able to see what everyone else voted for. A user can vote, but can't see how many people voted for the different options.

How the current advpoll works: view your advanced poll and vote. You'll see the results of what other people voted for - there's no way to hide those results.

The solution is to create a new permission called 'hide vote results' which hides vote results from the user with that permission to see votes, like so: http://drupal.org/files/advpoll_results.png

The permission is 'hide vote results' instead of 'view vote results' because we want this module to work out-of-the-box with sensible defaults. The default is that most people want their users to be able to view vote results, and only in special cases do we want to hide it.

If a user has the permission 'hide vote results' then this is what they'd see after voting: http://drupal.org/files/advpoll_hide-vote-results_vote.png
Of course, if they don't have the 'cancel own vote' permission then that button wouldn't show up.

Patch attached.

The only addition I can think to add to this is to allow a user to see their own vote, even if they can't see everyone else's.