Code cleanup etc.

src/metabase/api/common.clj

src/metabase/api/common/internal.clj

src/metabase/api/field.clj

src/metabase/api/permissions.clj

src/metabase/api/user.clj

src/metabase/core.clj

src/metabase/middleware.clj

src/metabase/models/card.clj

src/metabase/models/interface.clj

src/metabase/models/user.clj

src/metabase/plugins.clj

src/metabase/query_processor.clj

...abase/query_processor/middleware/add_implicit_clauses.clj

src/metabase/query_processor/middleware/cache.clj

src/metabase/query_processor/middleware/resolve.clj

src/metabase/query_processor/middleware/source_table.clj

test/metabase/api/common_test.clj

test/metabase/api/dataset_test.clj

test/metabase/models/card_test.clj

.../metabase/query_processor/middleware/permissions_test.clj