POC for the integrity check
Fixed toggle-all checkbox
Removed demo checks and CS
Added check if rules module is disabled
Show a hint about module configuration when manually sorting products (#1178)
Galleries can now have custom templates (#1194)
Rebuilt integrity check to use interface and checker classes
Implemented price table repair method
Added validation for variant orphans (#1129)
Use Haste Data for messages (fixes #1133)

This allows to customize the template for messages and write own
HTML code.
Fixed SQL query when deleting variant orphans
Do not use deprecated method
Check if class is abstract before creating model
CS
No more version_compare (see #1206)
CS
Updated changelog
Merge branch 'develop' into feature/integrity-check
Fixed callback for backend module
Merge branch 'feature/integrity-check' into develop