A settlement that BP is hammering out with victims of the massive Gulf oil spill finally provides a system for monitoring health concerns and compensating people whose illnesses are found to have a link to the disaster. Government and university doctors studying locals’ health haven’t found significant evidence of spill-related illnesses, but problems years from now remain a question mark. Gulf Coast residents say they’re happy their complaints are getting a serious look, even if they’ll face hurdles in proving that rashes, shortness of breath and other maladies were caused by the oil or chemical dispersants sprayed to break it up.