Developsinglesolution

Single solution PR providing a single Windows solution for windows projects and an additional solution for Xamarin Studio

*Note1
Currently has a dependency on the split "core" pull request for the windows solution

*Note2
The Linux Lidgren project has the same GUID as another Lidgren project and causes Xamarin Studio to exclude it on open, until this is resolved a simple workaround is to re-add the project after opening which works fine for builds

*Note3
Due to limitations with Xamarin studio licensing, the Android and iOS projects have been left out of VS as these require an enterprise license, also projects can only be built individually within Xamarin studio using the free license but still open / work fine