Fixed handling of & characters in XML element values

Fixes the issue where the resultant XML ends up in something like:
<Foo>This & that</Foo>
Which is now generates as:
<Foo>This &amp; that</Foo>
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 :)