pcl_kinfu_app saves camera pose to csv file.

The pcl_kinfu_app does not output the tracked camera pose, which can be useful i.e. for mobile robot navigation, or augmented reality.
This pull request adds a simple interface called CameraPoseProcessor, which receives the camera pose at every frame from KinFuApp.
The implementation CameraPoseWriter just writes all the camera poses to a file. The interface is easy to re-implement to do something else.
I've included an octave/matlab script to load and visualise the camera pose file.

Many thanks,
Marco Paladini <marco.paladini@ocado.com>