Make tolerance private; add accessor/mutator.
Make tolerance private; add accessor/mutator.

ranjan1990/mlpack,darcyliu/mlpack,ajjl/mlpack,darcyliu/mlpack,theranger/mlpack,palashahuja/mlpack,palashahuja/mlpack,ajjl/mlpack,theranger/mlpack,stereomatchingkiss/mlpack,ranjan1990/mlpack,theranger/mlpack,palashahuja/mlpack,stereomatchingkiss/mlpack,stereomatchingkiss/mlpack,darcyliu/mlpack,ajjl/mlpack,ranjan1990/mlpack