the library hogs my CPU to 100%, even when Kinect isn't connected

Proposed fix for the issue "the library hogs my CPU to 100%, even when Kinect isn't connected".
https://github.com/wieden-kennedy/Cinder-KCB2/issues/8

Not a perfect solution, as it may introduce some lag in some cases, but drops the CPU on my machine from 100% to 50%.