Update Kinjo main loop, incorporate calibration

-add ApplicationState
-getDepth and getRgb return reference to internal copy to speedup some
usages
-updateImages updates both images at the same time to hold them consistent
-add getPositionFromImagePointPx to calulate 3d position from 2d image
pixel
add estimatePositionFromImagePointPx to estimate the 3d position from the
8 surroudning and the given point incorporating only valid positions
-add renderTextCenter