unique_together integration in CW (alf+syt) * added in-DB representation of the constraint with a new entity type (CWUniqueTogetherConstraint) * the schema is now migrated on a sync_schema_props_perms(EType) call in the migration script * removed the migration commands provided in the first implementation

cubicweb-web: embedded-javascript-library usr/share/cubicweb/cubes/shared/data/jquery.js