Clamb gdb string output at 256 chars
Use zend_long_to_str in pcntl
Use zend_long_to_str in curl

Also use STR_ADDREF instead of maintaining a numeric_key flag.
Use smart_str_append_long in implode
Use zval_get_string in implode

Also get rid of separate case for IS_OBJECT - this is already
handled by the default branch.
Use zend_long_to_str in wddx