Explicitly set setupOwnerId on Error Settings
Don't insert Error_Settings__c if in test

This is done to avoid duplicate id errors on setupOwnerId.  When running in a test with seeAllData=false, getOrgDefaults returns an in memory Error_Settings__c object even if one exists in the org.  This is the expected behavior.  However, if that same test execution tries to then insert the in memory settings object, you get a duplicate id error.  Since tests destroy their data at the end anyhow, we only need to insert the new settings object if running outside a test.
Added explicit insert on Error_Settings__c default population
Added check before delete to make sure the object exists in db
Merge pull request #732 from SalesforceFoundation/feature/731-setupOwnerId-error

Fix Duplicate Id Errors on setupOwnerId in Tests