Load module `VuFindSearch' before main module
Fix incorrect method name

* VuFind/Search/Listener/NormalizeSolrSort.php (onSearchPre): Fix
incorrect method name.
Improve handling of indices in SOLR response

* VuFindSearch/Backend/Solr/Response/Json/RecordCollection.php
(getFacets): Fix wrong index in deserialized SOLR response.
(__construct): Use template to ensure existence of certain response
keys.
($template): Template of deserialized SOLR response.
Enable spellcheck if dictionary, create spelling query

* VuFindSearch/Backend/Solr/QueryBuilder.php
(createSpellcheckQuery): New function. Create spelling query.
(build): Enable spellcheck if dictionary, use new function.
New class: Iteratable NamedList `arrarr'

* VuFindSearch/Backend/Solr/Response/Json/NamedList.php: New
class. Iteratable NamedList `arrarr'.
New class: SOLR Spellcheck information

* VuFindSearch/Backend/Solr/Response/Json/Spellcheck.php: New
class. SOLR Spellcheck information.
Adjust path to ZF2 for VuFindSearch unit tests
Make SOLR parameter `fl' part of the query invariants

* VuFindSearch/Backend/Solr/Connector.php (getQueryInvariants)
(search): Make SOLR parameter `fl' part of the query invariants.