#22 RsrcGaddr(FRSTR) is inconsistent with rsrc_gaddr()

[Roger Burrows]

RsrcGaddr(FRSTR) returns the address of the free string. This is inconsistent with the original and GEMLIB bindings for rsrc_gaddr(), which returns a *pointer* to the address of the free string.
The same issue probably applies to FRIMG, although I haven't tested that.