message: detect AS and BR in guessElementSymbol
diff: /**
  - * Copyright (c) 2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
  + * Copyright (c) 2019-2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
  *
  * @author Alexander Rose <alexander.rose@weirdbyte.de>
  */
  @@ -28,7 +28,9 @@ export function guessElementSymbolTokens(tokens: Tokens, str: string, start: num
  ((c === 78 || c === 110) && (c2 === 65 || c2 === 97)) || // NA na Na nA
  ((c === 67 || c === 99) && (c2 === 76 || c2 === 108)) || // CL
  ((c === 70 || c === 102) && (c2 === 69 || c2 === 101)) || // FE
  - ((c === 83 || c === 115) && (c2 === 73 || c2 === 105)) // SI
  + ((c === 83 || c === 115) && (c2 === 73 || c2 === 105)) || // SI
  + ((c === 66 || c === 98) && (c2 === 82 || c2 === 114)) || // BR
  + ((c === 65 || c === 97) && (c2 === 83 || c2 === 115)) // AS
  ) return TokenBuilder.add(tokens, s, s + 2);
  }
  @@ -54,7 +56,9 @@ export function guessElementSymbolString(str: string) {
  if (l === 1) return str; // one char
  if (l === 2) { // two chars
  - if (str === 'NA' || str === 'CL' || str === 'FE' || str === 'SI') return str;
  + if (str === 'NA' || str === 'CL' || str === 'FE' || str === 'SI' ||
  + str === 'BR' || str === 'AS'
  + ) return str;
  }
  const c = str[0];
  