Changing name to DistButterfly

--HG--
rename : include/bfio.hpp => include/dist-butterfly.hpp
rename : include/bfio/rfio.hpp => include/dist-butterfly/Butterfly.hpp
rename : include/bfio/inuft.hpp => include/dist-butterfly/INUFT.hpp
rename : include/bfio/lnuft.hpp => include/dist-butterfly/LNUFT.hpp
rename : include/bfio/rfio/context.hpp => include/dist-butterfly/butterfly/context.hpp
rename : include/bfio/rfio/initialize_weights.hpp => include/dist-butterfly/butterfly/initialize_weights.hpp
rename : include/bfio/rfio/potential_field.hpp => include/dist-butterfly/butterfly/potential_field.hpp
rename : include/bfio/rfio/source_weight_recursion.hpp => include/dist-butterfly/butterfly/source_weight_recursion.hpp
rename : include/bfio/rfio/switch_to_target_interp.hpp => include/dist-butterfly/butterfly/switch_to_target_interp.hpp
rename : include/bfio/rfio/target_weight_recursion.hpp => include/dist-butterfly/butterfly/target_weight_recursion.hpp
rename : include/bfio/config.h.cmake => include/dist-butterfly/config.h.cmake
rename : include/bfio/constants.hpp => include/dist-butterfly/constants.hpp
rename : include/bfio/functors.hpp => include/dist-butterfly/functors.hpp
rename : include/bfio/functors/amplitude.hpp => include/dist-butterfly/functors/amplitude.hpp
rename : include/bfio/functors/phase.hpp => include/dist-butterfly/functors/phase.hpp
rename : include/bfio/inuft/context.hpp => include/dist-butterfly/inuft/context.hpp
rename : include/bfio/inuft/form_check_potentials.hpp => include/dist-butterfly/inuft/form_check_potentials.hpp
rename : include/bfio/inuft/form_equivalent_sources.hpp => include/dist-butterfly/inuft/form_equivalent_sources.hpp
rename : include/bfio/inuft/initialize_check_potentials.hpp => include/dist-butterfly/inuft/initialize_check_potentials.hpp
rename : include/bfio/inuft/potential_field.hpp => include/dist-butterfly/inuft/potential_field.hpp
rename : include/bfio/lnuft/context.hpp => include/dist-butterfly/lnuft/context.hpp
rename : include/bfio/lnuft/ft_phases.hpp => include/dist-butterfly/lnuft/ft_phases.hpp
rename : include/bfio/lnuft/potential_field.hpp => include/dist-butterfly/lnuft/potential_field.hpp
rename : include/bfio/lnuft/switch_to_target_interp.hpp => include/dist-butterfly/lnuft/switch_to_target_interp.hpp
rename : include/bfio/structures.hpp => include/dist-butterfly/structures.hpp
rename : include/bfio/structures/box.hpp => include/dist-butterfly/structures/box.hpp
rename : include/bfio/structures/constrained_htree_walker.hpp => include/dist-butterfly/structures/constrained_htree_walker.hpp
rename : include/bfio/structures/htree_walker.hpp => include/dist-butterfly/structures/htree_walker.hpp
rename : include/bfio/structures/low_rank_potential.hpp => include/dist-butterfly/structures/low_rank_potential.hpp
rename : include/bfio/structures/plan.hpp => include/dist-butterfly/structures/plan.hpp
rename : include/bfio/structures/point_grid.hpp => include/dist-butterfly/structures/point_grid.hpp
rename : include/bfio/structures/source.hpp => include/dist-butterfly/structures/source.hpp
rename : include/bfio/structures/weight_grid.hpp => include/dist-butterfly/structures/weight_grid.hpp
rename : include/bfio/structures/weight_grid_list.hpp => include/dist-butterfly/structures/weight_grid_list.hpp
rename : include/bfio/tools.hpp => include/dist-butterfly/tools.hpp
rename : include/bfio/tools/blas.hpp => include/dist-butterfly/tools/blas.hpp
rename : include/bfio/tools/flatten_constrained_htree_index.hpp => include/dist-butterfly/tools/flatten_constrained_htree_index.hpp
rename : include/bfio/tools/flatten_htree_index.hpp => include/dist-butterfly/tools/flatten_htree_index.hpp
rename : include/bfio/tools/lapack.hpp => include/dist-butterfly/tools/lapack.hpp
rename : include/bfio/tools/mpi.hpp => include/dist-butterfly/tools/mpi.hpp
rename : include/bfio/tools/special_functions.hpp => include/dist-butterfly/tools/special_functions.hpp
rename : include/bfio/tools/timer.hpp => include/dist-butterfly/tools/timer.hpp
rename : include/bfio/tools/twiddle.hpp => include/dist-butterfly/tools/twiddle.hpp