Ability to show only polar hydrogens (#663)

CHANGELOG.md

src/extensions/cellpack/model.ts

...l-plugin-state/builder/structure/representation-preset.ts

src/mol-plugin-state/manager/structure/component.ts

...avior/dynamic/selection/structure-focus-representation.ts

src/mol-repr/structure/visual/bond-inter-unit-cylinder.ts

src/mol-repr/structure/visual/bond-inter-unit-line.ts

src/mol-repr/structure/visual/bond-intra-unit-cylinder.ts

src/mol-repr/structure/visual/bond-intra-unit-line.ts

src/mol-repr/structure/visual/element-cross.ts

src/mol-repr/structure/visual/element-point.ts

src/mol-repr/structure/visual/element-sphere.ts

src/mol-repr/structure/visual/gaussian-density-volume.ts

src/mol-repr/structure/visual/gaussian-surface-mesh.ts

src/mol-repr/structure/visual/gaussian-surface-wireframe.ts

src/mol-repr/structure/visual/molecular-surface-mesh.ts

src/mol-repr/structure/visual/molecular-surface-wireframe.ts

src/mol-repr/structure/visual/util/bond.ts

src/mol-repr/structure/visual/util/common.ts

src/mol-repr/structure/visual/util/element.ts