Changed the icp example (pmicp) to accept initial translation/rotation input and allow to output the transformation matrices
Changed matrix for matrices as output suffix
Adapted the code to handle 2D point clouds and decided to split the initial/icp/complete transformation matrices in 3 differents files. It should be easier to post process the transformations.
Merge branch 'master' of https://github.com/smichaud/libpointmatcher into smichaud-master
update usage text and retab
Merge branch 'smichaud-master'