Switch to GNU GPLv3 all cpp source files

src/cluster/cluster.cpp

src/cluster/np_cluster.cpp

src/libnptm/Commons.cpp

src/libnptm/Configuration.cpp

src/libnptm/TransitionMatrix.cpp

src/libnptm/algebraic.cpp

src/libnptm/clu_subs.cpp

src/libnptm/lapack_calls.cpp

src/libnptm/logging.cpp

src/libnptm/magma_calls.cpp

src/libnptm/sph_subs.cpp

src/libnptm/tfrfme.cpp

src/libnptm/tra_subs.cpp

src/libnptm/types.cpp

src/sphere/np_sphere.cpp

src/sphere/sphere.cpp

src/testing/test_TEDF.cpp

src/testing/test_TTMS.cpp

src/trapping/cfrfme.cpp

src/trapping/clffft.cpp