Refactoring the image_pool for android, and adding some common utils for camera configuration.  Also experimenting with optimization - grayscale preview is way faster than color right now.

adding setup for some sample applications that use OpenCV on the android platform - nothing concrete yet - but soon.

Also, the androi-opencv.mk.in wasn't correct for one of the crystax NDK
build directory setups

adding cmake based android scripts and a reusable android library - samples to follow - haven't tested yet completely