#i124800# switch avmedia's QuickTime component to QTKit for now

because the QuickTime API is not available to 64bit clients. The switch to QTKit
is temporary only because it has already been deprecated in OSX 10.9. We'll have
to switch to OSX's AVFoundation framework instead soon.

Suggested by: Ariel Constenla-Haile <arielch@apache.org>