Bugfix: X-Total-Entries on /observations was broken.

For some reason that wasn't working w/ @pleary's pagination count
optimization. Many thanks to him for finding this solution.
Fixed extensions in atom and kml links; added atom mime type; caught format error
Merge pull request #285 from pleary/paths

Fixed extensions in atom and kml links; added atom mime type; caught format error
Minor style change for messages.
Reverting cache change, since it introduces deeper bugs w/ bbox queries.
Fixed issue with will_paginate and .to_a.total_entries
Added some comments to will_paginate_with_count.rb
Merge pull request #287 from pleary/paths

Fixed issue with will_paginate and .to_a.total_entries, commented
Place-based obs queries should work even if site has bounds.