Sort out inconsistencies in argument declarations

Some of our classes have inconsistencies between parameter parsing with zend_parse_parameters and the argument information documented with ZEND_ARG_ARRAY_INFO:

Follow-up: ZEND_ARG_ARRAY_INFO(0, options, 0) (i.e. not allowing null) also appears a few times in the driver, so we're actually less consistent about this than I thought. That is used for the Server's executeReadCommand and related methods, even though zend_parse_parameters uses |a! and accepts null. That's not even consistent with itself.