Fix issues with CDN multi-database support.

Use label instead of key, which is a reserved word on mysql.

Use correct data types on each of the three db's.

This will break dev db's if you try to upgrade and see the checksum
changed, it has not been released however so this is deemed acceptable.
Update for using keyword 'key' as column name
Merge branch 'master' into cdn-fixes

Conflicts:
	spec/candlepin_scenarios.rb
Correct variable
Merge pull request #429 from candlepin/cdn-fixes

Cdn fixes