Allow global privileges to be set on mysql users

- Add the ability to set global permissions (EE requires super)
- RE: https://github.com/opscode-cookbooks/database/issues/84, due to resource cloning, it's very tricky to set global privileges if you don't override the username of each resource and give it a unique name.
Pin back to chef-client 11.16.4
Fix for newer rubocop rules
Since this runs omnibus updater, pin back chef-client there too
Merge pull request #74 from rackspace-cookbooks/globalpriv_martinb3

Allow global privileges to be set on mysql users