Implement data preprocessing report

[arturossouza]

During the MoStress data preprocessing we have some logs about which steps are happening at the moment but we don't have a log which resume what happened for the data.

So the tasks here are:

1. Create a report at the end with importante info about the data preprocessing (how many windows were discarded , data size before and after, calculated weights, normalization type choosen and etc.). We still have to discuss the infos to be shown.
2. If necessary, improve the logs during the preprocessing.