[MERGE] Merge with kra568/tmp

src/LearningMethods/LearningMethods.cpp

src/LearningMethods/ParticleSwarm.cpp

src/Neuron/NeuronBiased.cpp

src/Solvers/DESolver.cpp

src/examples/net_test_1.cpp

src/examples/net_test_ode_1.cpp

src/examples/net_test_pde_1.cpp

src/examples/x2_fitting.cpp