Schema selection now in place

- Can change schemas from the menubar
- queries are made schema specific now
- Tutorial loads a separate set of questions and gets a new table when
the schema changes
- Free entry should now get only entries of the selected schema (old
method is still in place incase we want to add a "get all" selection)
- Renamed many instances of "Database" to "Schema" to reflect the
difference
- removed my old test connection method.