Cleanup unimplemented ZOOM_OVERRIDE stuff, old language entries, old comments and unused functions in shooting.c.
Override ISO conversion values for cameras that don't use 69 as the real / market conversion factor.
d20 - alternate raw buffer, fixes alternating corrupt DNGs. See http://chdk.setepontos.com/index.php?topic=10492.msg103618#msg103618 - release branch r3010