Added deepper test to check when a neuron or a neuron layer that will be
added is copied or not.
Checked methods that had a error in tests
Corrected the method that add a hidden layer
Added a test to check if the layers are right connected
Added a method to update all inputs
Checked constructors.

Now constructors will always update they output value
Enforced all methods to call joinAllInputs to ensure the join
It haven't changed anything
Added a comment to the joinAllLayers method
Added a lighter method to join layers.
Removed joinLayer method
Added a method to check output value
Added outputs test