ControlFlashConfigGet gets
the flash configuration of a Control object (control) and writes
it into the structure pointed to by config, and
also writes it into the implementation-specific structure pointed
to by external (if external is not
NULL).
The Control's flash configuration information in external
is in addition to the Control's flash configuration information
in config, i.e., the flash configuration information
in config and in external is not the
same information. Note that config or external
can be NULL (but not both NULL).