add errorFromDataSet(dataset) method for evaluating the error
on any given dataset with the current parameter configuration
in DeepNetworks.
add cases for returning the error value in DeepNetwork::errorFromDataSet.
use the specific numbers of samples directly from dataset
in DeepNetwork::errorFromDataSet.
parameterVector is also already initialized in DeepNetwork::initialize.
Merge branch 'new_extensions' of https://github.com/Ruun/OpenANN into Ruun-new_extensions

Conflicts:
	src/Net.cpp