Remove a part of CMake script that doesn't work any more.
Remove a part of CMake script that doesn't work any more.

No attempt to fix this part of the script is made because it change too
often (at each OS release) and no gain would result from a potential
fix.

SDKs are not stored in /Developer anymore with recent versions of Xcode.

Now the users should manually set the following variables :
 - CMAKE_OSX_SYSROOT,
 - CMAKE_OSX_DEPLOYMENT_TARGET,
 - CMAKE_OSX_ARCHITECTURES

Polyfructol/Fire,Polyfructol/Fire,Polyfructol/Fire,Polyfructol/Fire