Test for Bug 19438: Transaction errors are never displayed in database query view.

To test:

1. Open the Inspector
2. Go to the Databases panel
3. Click on the `InspectorTest` database
4. Enter the following text on the query input line: `INSERT INTO DisplaySQLTransactionError (test) VALUES (NULL)`

If the line of text you entered remains and an error line is output below it, you have passed the test.

If the line of text you entered disappears and no error line is output, you have failed the test.

If the line of text you entered remains and no error line is output, then the test has become invalid and needs to be modified to cause the error callback passed by the Inspector to `db.transaction` to be called.