Use dnsauth MySQL user, not root

[unix1]

While setting my dev environment, I thought instead of using MySQL root user, it should be using an app-specific user. This PR makes these changes:

• updates readme and config to start using the dnsauth user, instead of root
• removes WITH GRANT OPTION - it doesn't look like the app will be needing to grant other database users privileges

Note: existing dev environments would need to be adjusted:

• re-run MySQL commands in readme
• change your MySQL root user password to something long and cryptic

[unix1]

Yep, you're right, I did miss those spots. Fixed:

• updated root user references in 7c2c6c5
• removed reference to BGP output line in f7f62fe

[mrjones-plip]

thanks - looks good. merged!