Support PCL Profile 259

[colincnash]

The reflection API's available in PCL profile 259 are different to those in the current version of LightMock (profile 136) and so the NuGet package cannot be added. (http://blogs.msdn.com/b/dotnet/archive/2012/08/28/evolving-the-reflection-api.aspx)

I have created a fork where I have updated LightMock to profile 259 but this will break it for existing users on profile 136. It would be great if we could find a way to support both profiles. I'd be happy to work on it if you have any ideas as I am finding LightMock combined with xUnit very useful for writing unit tests within a PCL which I can then execute in each platform.

[seesharper]

259 seems to be the profile with the highest amount of compatibility. What would we break if we changed it to 259?

[colincnash]

It's just a couple of places where the reflection API's have changed. I'll send a pull request with my changes to support it although these probably need a review as they were written quite hastily. All the unit tests pass though.

It could probably do with some unit tests and possibly code changes around the async await functionality as well but I haven't had a chance to do these yet.