- Resolves VUFIND-1111

- Made jsonToHTML protected, as it does not need to be public
- Separated formatting of HTML and JSTree JSON so that neither depends on the other

- Restored missing "purge" button
- Made icons more consistent

- Thanks to Ere Maijala for the suggestion.

Some fix for new Zend Framework

Avoid PHP notices about undefined array fields when checking if the item can be requested from storage for holding rows with no items.

Fixed storage retrieval requests in VoyagerRestful to use correct config section and checkStorageRetrievalRequestIsValid() to always return bool instead of a string for patron blocks.