Merge branch 'master' into bond-repr

src/apps/structure-info/model.ts

src/mol-io/writer/cif/encoder.ts

src/mol-io/writer/cif/encoder/binary.ts

src/mol-io/writer/cif/encoder/text.ts

src/mol-io/writer/cif/encoder/util.ts

src/mol-math/geometry/symmetry-operator.ts

src/mol-model/structure/export/mmcif.ts

src/mol-model/structure/structure/unit.ts

src/mol-model/structure/structure/unit/rings.ts

src/mol-model/structure/structure/unit/rings/compute.ts