use shared mem to replace global dim_D, also reduce the size of m*m*n to m*n, fix the calculation problem in paralle reduction when the number is odd.
use shared mem to replace global dim_D, also reduce the size of m*m*n to
m*n, fix the calculation problem in paralle reduction when the number is odd.

yszheda/CUDA-knn-MPI,yszheda/OpenCL-knn-1GPU,yszheda/CUDA-knn-1GPU,yszheda/OpenCL-knn-1GPU