Fixes

1. Fixed: In API call getCustomers, search fields searchCode, searchRegistryCode, searchVATNo, searchEmail and searchMobile did not return a matching customer if the search word contained an underscore.
2. Fixed: API call saveAddress produced an error when updating the address of a deleted customer.
3. Fixed: API calls getProductGroups, getCustomers, getAccountStatements returned links to other resources starting with http://. These links have now been updated to https://.
4. Fixed: URLs returned by API call getAccountStatements contained errors.