Adds interfaces for search/indexing and updates existing classes to implement interfaces
Removes solr specific indexing code from core
Adds cli commands for indexing
Adds generic indexing layer
Adds LinkService and updates existing Entities to provide methods to indexing services
Removes duplicate declaration of getIssue method and adds false check to getWebcode
Merge remote-tracking branch 'pawel/attachments' into CS-4921-new
CS-4921: Removes old indexing code
CS-4921: Implements DocumentInterface in article entity
CS-4921: Implements DocumentInterface for comments
CS-4921: Adds methods needed for indexing
CS-4921: Implements RepositoryInterface in article repository
CS-4921: Implements RepositoryInterface for comments
CS-4921: Implements RepositoryInterface for users entity
CS-4921: Adds shortname property and methods to section
CS-4921: Implements DocumentInterface for User
CS-4921: Add method needed for indexing to image service
CS-4921: Adds QueryInterface and AbstractIndexCommand
Merge branch 'CS-4921' into CS-4921-new

Conflicts:
	newscoop/library/Newscoop/Entity/Publication.php
	newscoop/library/Newscoop/Entity/Repository/ArticleRepository.php
	newscoop/library/Newscoop/Search/QueryInterface.php
	newscoop/library/Newscoop/Tools/Console/Command/AbstractIndexCommand.php
CS-4921: Adds filter topic_strict