Closes issue #278
Refactoring validation
Revert "Remove inline style"

This reverts commit a7674db6a7d608c62c960500ee76bd8e0b8e9dce.
Revert "Done"

This reverts commit 4102bff6453b91dfc8a834f7d8d09f82af49a766.
Remove inline style
Revert "Refactoring validation"

This reverts commit 866c5570ba14d457620da41a1b29488e3bb911ee.
Return a thumbnail only if the item has an image field and the field is visible

closes #278
Update change log
Merge pull request #279 from collective/issue_278

Do not break if item has not image field