Merge pull request #1 from jindw/master

updating fork
parseFromString now renders entirely plain text documents as textNode

This pull request resolves the issue where parseFromString throws error
when given plain text to parse.

Summary of issue:

This example code throws the following error: `source code out of
document root`

```js
var xmldom = require('xmldom'),
    DOMParser = xmldom.DOMParser,
    XMLSerializer = new xmldom.XMLSerializer(),
    string = 'plain text',
    doc = new DOMParser().parseFromString(string, 'text/html'),
    s = XMLSerializer,
    str = s.serializeToString(doc);
console.log(str);
```

The resulting document given is this:

```js
{ doctype: null,
  implementation: { _features: {} },
  childNodes: {},
  documentURI: undefined }
```

It should return a single textNode childNode instead of an empty set of
childNodes.
Merge pull request #70 from kethinov/master

Merge empty parse from string.