AV Foundation based capture for OS X

For Consideration:
The capture class `CaptureImplAvFoundation` used by iOS, is usable as-is by OS X. The *AV Foundation* APIs needed for capture were added in OS X 10.7, conveniently Cinder's minimum supported version. After this PR, this should leave the movie playback and writer classes as the remaining consumers of *QTKit* and *QuickTime*.

**NOTE** - This PR requires OS X applications to additionally link to *AVFoundation.framework* and *CoreMedia.framework*.

All OS X sample project files have been updated to add both frameworks and further yet, normalize the linked frameworks (several linked to *Carbon* still :tired_face:), update project settings to the 5.1 Beta 4 suggestions (perfectly backward compatible) and *all* but the QuickTime samples can build 64-bit (native arch for Debug and i386/x86_64 fat for Release).

I have tested that all samples compile and run with Xcode 5.1 Beta 4 on 10.9.1 and Xcode 5.0.2 on 10.8.5 via the *_AllSamples* project. Some projects cannot be run from the *_AllSamples* project due to resource loading, but that is another story. While I don't have a machine running 10.7, I did install 10.7.5 in a VM and tested that all samples compile with Xcode 4.6.3 - I didn't have any luck accessing the build-in iSight camera or a USB webcam from within the VM (VMWare Fusion 6.0.2), but I'm hoping someone else can quickly validate the *CaptureBasic*, *CaptureAdvanced* and *rotatingBox* projects on 10.7.