[R-sig-Geo] Building rgdal 0.6-7 on Mac

[Rich Grenyer]

> On Linux i386 and x86_64, and Windows i386, everything looks OK.

I built 0.6-7 from source this morning on i386-apple-darwin8.11.1  
without problem, linking to the Kyngesbury frameworks; it didn't fail  
with that error.

Rich