Opencv: Add OpenCV 3.0

-Support for new PACKAGECONFIGS
-Merge with opencv-samples

Since it is not backward compatible with 2.x and cannot be installed in
parallel it has a DEFAULT_PREFERENCE of -1.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>