Fix 3.0 erroneous merge
Revert "Fix 3.0 erroneous merge"

This reverts commit a44e82b76f38917a535d3537da798bc6b268ce3a.
Improved EntryModelGenerator
Compile relations to the model
Fix array to string conversion error
We don't need static cache here
Add the Data folder to the installer writable folder list
Merge branch '2.3/develop' of github.com:pyrocms/pyrocms into 2.3/develop

Conflicts:
	system/cms/modules/streams_core/field_types/relationship/src/Pyro/FieldType/Relationship.php
	system/cms/modules/streams_core/src/Pyro/Module/Streams_core/StreamModel.php