Merge branch 'release-1.6'

CHANGELOG.txt

CMakeLists.txt

modules/conop/doc/aminoacid.rst

modules/conop/pymod/export_amino_acids.cc

modules/conop/src/amino_acids.cc

modules/conop/src/amino_acids.hh

modules/conop/tests/CMakeLists.txt

modules/conop/tests/test_amino_acids.cc

modules/geom/src/vecmat3_op.cc

modules/geom/src/vecmat3_op.hh

modules/io/pymod/__init__.py

modules/io/pymod/wrap_io.cc

modules/io/src/mol/dcd_io.cc

modules/io/src/mol/load_entity.cc

modules/io/src/mol/load_entity.hh

modules/mol/alg/src/svd_superpose.cc

modules/mol/base/pymod/export_surface.cc

modules/mol/mm/doc/buildingblock.rst

modules/mol/mm/doc/forcefield.rst

modules/mol/mm/doc/integrators.rst