Latest snapshot

Updates on:
- Normalization class
- TrainingSet class
- NormalizationWidget class
- TrainingSetDialog class

Added Mean Distance Normalization, fixed Sigmoid Normalization an Tanh
Normalization
Improve performance and funtionality on NormalizationWidget class
Added some normalization methods on Normalization and TrainingSet Class
to help to the normalization proccess.
Added some methods on LabeledSipinBoxWidget to improve functionality