camera.h cleanup and corrections from nafraf in http://chdk.setepontos.com/index.php?topic=650.msg103955#msg103955 - trunk r3027a3200: Define CAM_EXT_TV_RANGE, undefine CAM_HAS_IRIS_DIAPHRAGM and CAM_HAS_ERASE_BUTTONa3000: Define CAM_EXT_TV_RANGE, undefine CAM_HAS_IRIS_DIAPHRAGMixus105: Undefine CAM_HAS_IRIS_DIAPHRAGMixus300: Define CAM_EXT_TV_RANGEFix comments in: a3000, a3100, ixus1000, ixus110, ixus115.