remove ndims
better CMMSolver init
Merge pull request #18 from hadim/remove_ndims2

Remove ndims2
Rename get_costmat to cost_matrice and move outside of LAPSolver
Cleanup
New way to define cost_matrice
Rename matrice to matrix
Merge branch 'new_cost_impl' of github.com:hadim/lap_tracker into new_cost_impl