Check if the parent actually loaded, before trying to set its thumbnail...

In batches, it's easier to first ingest all the pages, before the book object...
...  because the book object didn't exist, it was causing the batch to break.
Pushing search results alter from manidora to book
Named the form elements the same as the variables used in
variable_get/set.
Merge pull request #58 from daniel-dgi/7.x

Pushing search results alter from manidora to book
Update islandora_book.module

Avoid reusing a variable.
Merge pull request #57 from adam-vessey/7.x

Check if the parent actually loaded, before trying to set its thumbnail....