Summary: Suggest the MySQL mode STRICT_ALL_TABLES during setup if it is not set. Small improvement to the phabricator.developer-mode comments. Test Plan: Set the global sql_mode to include or exclude STRICT_ALL_TABLES and check for desired behavior. Reviewers: epriestley Reviewed By: epriestley CC: aran, Korvin Differential Revision: https://secure.phabricator.com/D4803