Issue #2231: Attempt to fix segfault, when copying labels. LDA needed to be updated to generate the Wrapper correctly.

add channel 3 support
add fast way Between CPU and GPU for the data which is aligned

Signed-off-by: yao <bitwangyaoyao@gmail.com>

facerec.cpp: Removed Original LBP wrapper, because it is not in use and therefore generates a warning.

facerec.cpp: Added an exception to the LBP extraction, so now a meaningful exception is thrown if the wrong image type was given. Thanks to Eric Christiansen for reporting.

Android 4.1.1 native camera fix. BufferQueue class is used instaed of Surface texture. Includes in cmake updated.

FaceRecognizer supports updating a model now. Documentation has been updated to reflect latest changes.

building descriptor index on target capture
simple AR experiment (work in progress)

Updated the train method to be an InputArrayOfArrays, so the Python wrapper now generates the correct code (and it works).

Updated the documentation to (1) reflect the latest changes and (2) answer some questions I were asked.