updated dependencies version to be compatible with XamarinStudio

Hi,

I have updated the dependencies version to be compatible with XamarinStudio. 

Probably worth generating a new add-in repo url for XamarinStudio and keeping the current one for previous MonoDevelop versions. If you decide to create a new repo/branch for Xamarin and want me to send this pull request over there just let me know.

Many thanks,
Franc