Finish pending tests for basic industry facility.
Change basic industry facility to use a schematic name and do lookups, rather than holding an instance.
Change EditFactoryWidget to use schematic_name rather than schematic instance.
Add Schematic singleton test case to Basic Industrial Facility.
Add unit tests for advanced industry facility.
Change advanced industry facility to use a schematic name and do lookups, rather than holding an instance.
Add tests to make sure we error if tryin to set a schematic of a wrong p-level.
Fix typos in error output.
Add assertions stating that the observer should not be set when a schematic of the wrong p-level is loaded.
Add unit tests for high tech industry facility.
Change high tech industry facility to use a schematic name and do lookups, rather than holding an instance.