message: added alt_id to element label
diff: @@ -9,7 +9,7 @@ import { Unit, StructureElement, StructureProperties as Props, Link } from 'mol-
  import { Loci } from 'mol-model/loci';
  import { OrderedSet } from 'mol-data/int';
  -// for `labelFirst`, don't create right away to avaiod problems with circular dependencies/imports
  +// for `labelFirst`, don't create right away to avoid problems with circular dependencies/imports
  let elementLocA: StructureElement
  let elementLocB: StructureElement
  @@ -63,7 +63,8 @@ export function elementLabel(location: StructureElement) {
  const seq_id = Props.residue.auth_seq_id(location)
  const comp_id = Props.residue.auth_comp_id(location)
  const atom_id = Props.atom.auth_atom_id(location)
  - label = `[${comp_id}]${seq_id}:${asym_id}.${atom_id}`
  + const alt_id = Props.atom.label_alt_id(location)
  + label = `[${comp_id}]${seq_id}:${asym_id}.${atom_id}${alt_id ? `%${alt_id}` : ''}`
  } else if (Unit.isCoarse(location.unit)) {
  const asym_id = Props.coarse.asym_id(location)
  const seq_id_begin = Props.coarse.seq_id_begin(location)
  