The type column is now indexed
Added method to get root entity
Using new method in tableNameForEntity:
When creating a many-to-many relationship table a type column is now added if needed
Entity type is not also inserted into the many-to-many relational table
When deleting or updating items in the man-to-many relational table the root entity column name is used
When looking up man-to-many relations the destination entity type is returned so the correct subclass of entity can be created
Using the relational description instead of the object entity when deleting and updating objects
Added flag to columnNamesForRelationship:withQuotes: to check if columns types needed to be added, this is to distinguish the difference between table creation and fetch requests