Fixed handling of & characters in XML element values

Fixes the issue where the resultant XML ends up in something like:
&lt;Foo&gt;This &amp; that&lt;/Foo&gt;
Which is now generates as:
&lt;Foo&gt;This &amp;amp; that&lt;/Foo&gt;
Another way was using CDATA, but I'm not a real fan of that.

I have never used GitHub before, so I have no idea at the moment how I can update my repository from the master original master, but I hope you see my changes :)