Make camcv subproject

This is according to the instructions on
http://thinkrpi.wordpress.com/2013/05/22/opencvpi-cam-step-3-create-your-own-project/.
The project compiles but the sources ahve mostly remained untouched. I have
changed several paths in order to be able to meet include requirements.

To test: Build from within source directory using:

``
cmake .
make
``

This should make an executable in the source directory called camcv. It should
behave exactly like raspistill.