Ability to flag entry for fix from the map

There are many entries that are wrong or outdated. We should provide at the least a boolean flag to mark the entry for review. Preferably, however, would be the ability to let us know what's wrong with that entry.

Preferred to use pre-determined selector (multi-select checkboxes probably best):
- wrong location on map
- address wrong
- site closed
- site moved
- changed name
- wrong URL
- other

...and a free-form entry to add details. Free-form entry should have captcha. Should also require a name and email for contributor.