Fixed copyright notices.

src/@dseries/baxter_king_filter.m

src/@dseries/cumprod.m

src/@dseries/cumsum.m

src/@dseries/dseries.m

src/@dseries/save.m

src/@dseries/vertcat.m

src/initialize_dseries_toolbox.m

src/read/load_csv_file_data.m

src/read/load_m_file_data.m

src/read/load_mat_file_data.m

src/utilities/from/from.m

tests/runalldseriestests.m