dns: The 'Delete' button at the top of the edit-record page was slightly misleading and leads you to believe you're deleting a record, not the entire domain.
service: handle invoices linked to services correctly upon deletion, instead of deleting all InvoiceItems and giving the user a surplus of credit.
Merge pull request #9 from nasonfish/master

service, dns: Fixed a misleading button, handle deleted services' invoices correctly.