Added input matrix
Removed matrix's layers input
Created a basic test for MultilayerPerceptron
Added default constructor to the tests
Implemented test to check default constructor
Implemented test to check constructor with ArrayList of NeuronLayer
Implemented test to check default copy constructor
Implemented test to check getLayers method
Update getLayers test
Updated test to check a MultilayerPerceptron copy
Created equals method
Added overhead to get method.

Now get method can return a neuron if you specify a subindex.
Created a test to check new get method
I can't remember the changes
Added a method to get the input layer
Created a test to check getInputLayer method
Corrected getInputLayer method.

Now when you try to get a input layer from an empty MutilayerPerceptron
you will receive a null pointer.
Added commenters to the getInputLayer method
Added getInputLayerSize

This method will return the size of the input layer. If the input layer
does not exist, it will return zero.
Added a test to check getInputLayerSize method