Merge with master

.gitignore

build_io.sh

configure.ac

gc_out2_test.html

gc_out3_test.html

gc_out4_test.html

gc_out5_test.html

gc_out6_test.html

gc_out7_test.html

gc_out_test.html

gc_plot2_out_test.html

gc_plot_out_test.html

src/CSVWriter/CSVWriter.hpp

src/CSVWriter/CSVWriter_unit_tests.hpp

src/CSVWriter/csv_multiarray.hpp

src/GraphMLWriter/GraphMLWriter.hpp

src/GraphMLWriter/GraphMLWriter_unit_tests.hpp

src/HDF5_XdmfWriter/HDF5_XdmfWriter.hpp

src/HDF5_XdmfWriter/HDF5_XdmfWriter_point_set.hpp

src/HDF5_XdmfWriter/HDF5_XdmfWriter_unit_tests.hpp