Improved history check.

src/main/resources/db/migration/V1_1__create_history_schema.sql

@@ -0,0 +1,11 @@
+CREATE OR REPLACE VIEW musicbrainz_enricher.release_work_queue AS
+SELECT *
+FROM musicbrainz_enricher.release_with_relationships r
+		 LEFT JOIN musicbrainz_enricher.release_history_entry rhe ON r.gid = rhe.release_gid
+WHERE rhe.release_gid IS NULL;
+
+CREATE OR REPLACE VIEW musicbrainz_enricher.release_group_work_queue AS
+SELECT *
+FROM musicbrainz_enricher.release_group_with_relationships rg
+		 LEFT JOIN musicbrainz_enricher.release_group_history_entry rghe ON rg.gid = rghe.release_group_gid
+WHERE rghe.release_group_gid IS NULL;