Check for Customization with SCAPI

Two new SCAPI response headers are available to check for custom requests and resulting hook execution errors.

1. sfdc_customization–indicates whether customization has been applied during the request execution. Currently, the only possible value for the header is “HOOK”, which indicates that a hook execution was registered.
2. sfdc_customization_error–if the value is “1", an error occurred within a hook execution.