Added camera calibration sample for android

Added camera calibration sample for android. It is useful for pinhole cameras. Sample based on "Camera calibration With OpenCV" tutorial (http://docs.opencv.org/trunk/doc/tutorials/calib3d/camera_calibration/camera_calibration.html). It uses standard OpenCV asymmetric circles grid patern 11x4 (https://github.com/Itseez/opencv/blob/2.4/doc/acircles_pattern.png). The results are the camera matrix and 5 distortion coefficients.

When pattern is recognized it's highlighted. Tap on highlighted pattern, to capture pattern corners for calibration. When you've captured necessary amount of pattern corners, press "Calibrate" button for performing camera calibration. Results are logged in current version.

Going to add next features:
1. Display calibration error and save calibration results.
2. Show undistorted preview.
3. Show comparison real/undistorted view: half screen for every.
4. Add help with description of calibration process and tips.