allow CV scripts to create sprite parts with crazy invalid data, add nicer error message for non-CV case
allow CV scripts to create sprite parts with crazy invalid data, add nicer error message for non-CV case

bdonlan/openc2e,bdonlan/openc2e,ccdevnet/openc2e,crystalline/openc2e,crystalline/openc2e,bdonlan/openc2e,crystalline/openc2e,bdonlan/openc2e,ccdevnet/openc2e,ccdevnet/openc2e,crystalline/openc2e,crystalline/openc2e,ccdevnet/openc2e,ccdevnet/openc2e,ccdevnet/openc2e