Refactor and add to AJAX tests

* Test for error checking
  * Add query mock to test this
Extra error check in language
Clean up updater

* No new tests
* Moving timestamp syncing to updater only
* Minor query cleanup
Clean up and test the saver

* Return error codes in the editor
* Test for saving with new file
ALL THE ERROR CHECKING

Also, documentation
* Protect functions not part of the API
Error checking on front end

* Mostly console.log'ing and some output
* Missing admin_notice accidentally stashed + test var in saver
* Add messages to AJAX
Merge branch 'feature/unit-tests-and-error-checking' into develop

* feature/unit-tests-and-error-checking:
  Error checking on front end
  ALL THE ERROR CHECKING
  Clean up and test the saver
  Clean up updater
  Extra error check in language
  Refactor and add to AJAX tests