(Bug 44474) Allow exceptions from efSchemaValidate

This fixes the whole 'Exception of type MWException' thingamabob when
trying to save schema that are valid JSON but invalid JSON Schema.

Change-Id: Ib0c824e94e40144fadd6a780ec72074db171fa93
(Bug 44781) Sort column names lexicographically

Also sets `echo=True` kwarg for sqlite engine; nosetests captures
stdout/stderr anyway.

Change-Id: Iee8e4799df72dbf3f1d0c06d548b405208cbae69