Robust serialisation options for dynamics

[jordangray]

A couple of issues have cropped up which aren't going to be easy to fix. As a stopgap measure, consider making it possible to serialise dynamic types, even without all the fancy custom formatting options.

[jordangray]

I've done some initial work at splitting out the serialisation logic, and should be making this available soon. It's nowhere near as tidy or fully-functional as the JSON.NET approach, but it's a start!

[jordangray]

Update: current work continues on my local fork; see https://github.com/jordangray/WebApiContrib.Formatting.Xlsx if you want to try it out.

[jordangray]

Running a bit late on this as I was on holiday recently, but should be taking a closer look this weekend before committing. Unsure about the nomenclature I've been using; need to think about this in more detail.

[jordangray]

Basic support for ExpandoObject added in #47. You'll be able to get this soon on NuGet as 2.0.0-pre, or you can grab it now in the pre branch.