now it's PCL-based: reading files and visualizing results.
add FindFlann.cmake from flann github
icp using flann-based search
add openmp
source/target inverted
flann-based: minor fix
PCL-based visualization for all: emicp, emicp-cpu, and softassign
icp.cpp interface takes pcl::PointCloud

icp.cpp interface takes pcl::PointCloud
using boost::shared_array
emicp_cpu.cpp interface taks pcl::PointCloud
all algorithm interfaces take pcl::PointCloud
delete unused function
simplified (easy to see) use of shared memory