Got rid of include guards in preference of #pragma once.
	modified:   TODO
	modified:   evaluation_measures.hpp
	modified:   input_readers.h
	modified:   lambdarank.hpp
	modified:   lambdarank_optimize.hpp
	modified:   ltr_algorithm.hpp
	modified:   ltr_common.hpp
	modified:   ml/learning_rate.h
	modified:   ml/linear_regression.h
	modified:   ml/ml_model.h
	modified:   ml/neural_net.h
	modified:   ml/neural_net_activation.h
	modified:   ml/regression_tree.h
	deleted:    ml_algorithm.hpp
	modified:   object.h
	modified:   ranknet.hpp
	modified:   ranknet_lambda.hpp