Attach (recommended) or Link to PDF file here:
http://mariovalle.name/SciViz/1-s2.0-S0097849310001846-main.pdf

Configuration:
- Web browser and its version: Using pdf.js from Node.js through npm package `pdfjs-dist`
- Operating system and its version: Windows 10 64bits
- PDF.js version: 2.6.347
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the file in acrobat
2. In document properties look at the Author field: it is `Samuel Silva; Beatriz Sousa Santos; Joaquim Madeira`
3. Look at  Additional metadata > advanced > dc:creator. It is marked as `seq container` and contains the 3 authors.
4. Using the code below gives: `"Author": "Samuel Silva"` that is, only the first one. And `"dc:creator": "Samuel SilvaBeatriz Sousa SantosJoaquim Madeira"`, that is the three authors squashed together without separators.

What is the expected behavior? (add screenshot)
In both fields the three authors as a single string with some sort of separator between them. Note that other pdf files that contains multiple authors already have them as a single string with names separated by commas.

The code used:
```
var pdfjsLib = require("pdfjs-dist/es5/build/pdf.js");
var pdfPath = "http://mariovalle.name/SciViz/1-s2.0-S0097849310001846-main.pdf";
var loadingTask = pdfjsLib.getDocument(pdfPath);
loadingTask.promise
  .then(function (doc) {
    var lastPromise;
    lastPromise = doc.getMetadata().then(function (data) {
      console.log(JSON.stringify(data.info, null, 2));
      if (data.metadata) {
        console.log(JSON.stringify(data.metadata.getAll(), null, 2));
      }
    });
  });
```
"<!DOCTYPE lolz [" +
      '  <!ENTITY lol "lol">' +
      '  <!ENTITY lol1 "&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;">' +
      '  <!ENTITY lol2 "&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;">' +
      '  <!ENTITY lol3 "&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;">' +
      '  <!ENTITY lol4 "&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;">' +
      '  <!ENTITY lol5 "&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;">' +
      '  <!ENTITY lol6 "&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;">' +
      '  <!ENTITY lol7 "&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;">' +
      '  <!ENTITY lol8 "&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;">' +
      '  <!ENTITY lol9 "&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;">' +
      "]>" +
      '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">' +
      '  <rdf:Description xmlns:dc="http://purl.org/dc/elements/1.1/">' +
      "    <dc:title>" +
      "      <rdf:Alt>" +
      '        <rdf:li xml:lang="x-default">a&lol9;b</rdf:li>' +
      "      </rdf:Alt>" +
      "    </dc:title>" +
      "  </rdf:Description>" +
      "</rdf:RDF>";
    const metadata = new Metadata(data);
    expect(metadata.has("dc:title")).toBeTruthy();
    expect(metadata.has("dc:qux")).toBeFalsy();
    expect(metadata.get("dc:title")).toEqual("a&lol9;b");
    expect(metadata.get("dc:qux")).toEqual(null);
    expect(metadata.getAll()).toEqual({ "dc:title": "a&lol9;b" });
  });
});