Fix MacOS platform macro for Qt 5.
Fix MacOS platform macro for Qt 5.

Ignore-this: 20a784585cb58b0301e18add010d24f1

darcs-hash:20140218214856-4d2ae-0e2ea0637f0c1bd57dc59e484e9336cdb2579702

johntyree/HsQML,johntyree/HsQML