DOC: Docker info in README_SETUP.md, fixed procedure documentation.

README_SETUP.md

@@ -73,5 +73,11 @@ with the then current version of the stored entities.
 ## Unit tests
 
 * We use [MyTAP-1.0](https://hepabolu.github.io/mytap/) for unit tests.
+* Requirements:
+    * mysqladmin
+    * mysqldump
+    * mysql client program
 * Tests are in `tests/test_*.sql`.
 * Run `make test`.
+    * Alternatively, to run the tests in a containerized MariaDB instance, run `make test-docker`,
+      followed by `make test-docker-stop`.

procedures/query/applyBackReference.sql

@@ -30,7 +30,7 @@ DELIMITER //
 /**
  * Process a set of entities, keeping those which are referenced in a specific way.
  *
- * This procedure filters a source table and writes the result is written into a target table.  If
+ * This procedure filters a source table and writes the result into a target table.  If
  * the target table is not given, all non-matching entries are deleted from the source table
  * instead.
  *
@@ -58,8 +58,7 @@ DELIMITER //
  * versioned : boolean
  * If True, if a reference is versioned (references to specific versions of entities), the target
  * candidate's version must match.  Therefore, the sourceSet and targetSet must have a `_iversion`
- * column as well (unless sourceSet is the `entities` table).  If `sourceSet` is the `entities`
- * table, unversioned references will result in all versions of a referenced candidate being returned.
+ * column as well (unless sourceSet is the `entities` table).
  *
  */
 CREATE PROCEDURE db_2_0.applyBackReference(in sourceSet VARCHAR(255), targetSet VARCHAR(255),