OpenNI updates

Recently I updated the OpenNI library to version 1.3.4.3 in the unstable branch, but playing from recorded files doesn't work after that. Then I switch back to  the latest version (1.3.3.6) in the master branch which works for playing recorded files.

The OpenNI developers are not very responsive to pull requests. In particular, the bug that I mentioned in the earlier post that is related to the wrong use of memcpy has not been fixed. So I forked the project and added the fix. I also added a method copyToBuffer to wrapper/OpenNI.java/src/org/OpenNI/Map.java so that we only need to allocate the buffer for the depth or image map once.