CMake: work-around for CodeBlocks lack of framework support.

CodeBlocks is utterly ignorant of frameworks on Mac, and won't report
framework paths. The work-around is to check if the include path ends in
".framework", and if so, add the parent directory as framework path.

Task-number: QTCREATORBUG-11445
Change-Id: I794dd72d755d5593e36ebf59543d0a5e9fda3cce
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>