These attributes correspond to one field in the object's embedded gadget
structure--the gadgettext field.  setting any of these attributes copies
the attribute's value blindly into the GadgetText field.  In addition,
setting GA_Text also sets the gflg_labelstring flag in gadget.flags and
setting GA_LabelImage sets the gflg_labelimage flag in gadget.flags.  the
GA_IntuiText attribute must be an intuitext pointer, as with old-style
gadgets.  GA_Text takes a pointer to a NULL- terminated string (UBYTE *).
GA_LabelImage takes a pointer to a (Boopsi) image.  Note that most gadget
classes do not support GA_Text and GA_LabelImage.  See the description of
specific gadget classes for more details.