Added: Sort clause for sections
Added: DatePublished sort clause for Solr
Added: methods to enqueue operations to be run at transaction commit
Added: more aliasing
Added: Implementation of the MultipleStringField
Changed: commenting code that doesn't work yet

Object states does not seem to be implemented completely, commenting for
now.
Changed: adapted Solr fixtures against results received
Added: Signals and Slots for Solr
Added: ContentService integration tests to Solr
Added: ContentName Solr sort clause
Changed: methods doesn't return anything
Added: Location removal implementation in Solr
Fixed: unknown currentUser property with SignalSlot Repository
Fixed: 'group' should be a multiple identifier field
Added: _fixtures/Solr/SortContentName.php
Added: missing FieldType config in SetupFactory\LegacySolr
Added: \eZ\Publish\SPI\Persistence\Content\Location\Handler::loadSubtreeIds
Fixed: Added missing buildFieldType() method to SignalSlot\FieldTypeService
Added: Copy subtree implementation in Solr
Added: Move subtree implementation in Solr