v3 support

Thanks for this - just used it in a customer app :)

I've also just updated our version to v3

The partial code is listed in https://gist.github.com/slodge/5833029

I can try to get this together as a proper pull request if you're interested? If you are, let me know and I'll try to do it next week :)

Thanks again

Stuart

Start by reviewing the partial v3 implementation in the linked gist and the current MvvmCross.AlexeysExtensions repository. Compare the existing extension with the v3 changes to determine the required scope; done means v3 support is implemented and validated, though no test or validation entry point is named in the issue.

Written by the indexing model from the issue text.