Ability to create tables without system columns

[RFSH]

When history support was added to ermrest, we changed this tool to inject the system columns into the table definitions. This reduced the number of changes that we needed to do in ermrestjs and chaise, but as a result, we cannot test scenarios where system columns are missing.

From this repository's perspective, we should be able to achieve this by adding a simple dont_add_system_columns flag to table definitions. But, to ensure that ermrest allows such tables, we must first change the ermrest configuration. And this would affect everybody else that is using our dev server. So I created an issue for now.

We should discuss whether testing these scenarios is important, and if it is, what are the configuration changes that we need to do, and how they affect other projects/scenarios/people.