Merge branch 'master' into state_representation

src/apps/canvas/index.ts

src/apps/canvas/structure-view.ts

src/apps/canvas/volume-view.ts

src/mol-geo/geometry/direct-volume/direct-volume.ts

src/mol-geo/geometry/geometry.ts

src/mol-geo/representation/structure/index.ts

src/mol-geo/representation/structure/units-visual.ts

...representation/structure/visual/gaussian-density-point.ts

...epresentation/structure/visual/gaussian-density-volume.ts

.../representation/structure/visual/gaussian-surface-mesh.ts

...esentation/structure/visual/gaussian-surface-wireframe.ts

src/mol-geo/representation/structure/visual/util/common.ts

src/mol-geo/representation/volume/direct-volume.ts

src/mol-gl/renderable/direct-volume.ts

src/mol-gl/renderable/gaussian-density.ts

src/mol-gl/renderable/lines.ts

src/mol-gl/renderable/mesh.ts

src/mol-gl/renderable/points.ts

src/mol-gl/renderable/schema.ts

src/mol-gl/shader-code.ts