Refactor perceptron program to load/save models.
Refactor perceptron program to load/save models.

Now you can save perceptrons, which is a big functionality boost.  Also the documentation has been redone.

lezorich/mlpack,stereomatchingkiss/mlpack,ranjan1990/mlpack,ranjan1990/mlpack,erubboli/mlpack,theranger/mlpack,darcyliu/mlpack,stereomatchingkiss/mlpack,palashahuja/mlpack,theranger/mlpack,BookChan/mlpack,stereomatchingkiss/mlpack,darcyliu/mlpack,lezorich/mlpack,darcyliu/mlpack,ajjl/mlpack,BookChan/mlpack,BookChan/mlpack,ajjl/mlpack,erubboli/mlpack,palashahuja/mlpack,ranjan1990/mlpack,lezorich/mlpack,palashahuja/mlpack,ajjl/mlpack,erubboli/mlpack,theranger/mlpack