[trunk] QMake default deployment target is now set to OSX 10.8
[trunk] OSX dylibs do not require the versioned symlinks that Unix does. The Apple design guidelines indicate using the major version number in the dylib filename, e.g. libMyDynamicLib.MajorVersion.dylib. And then set the --current_version and --compatibility_version flags on the linker. QMake does not support this fully, and so symlinks are generated.