Convert the .net project to a portable project so i can target more platforms

[AnderssonPeter]

To get the broadest possible portable library you can target the following:
.Net 4.5
Windows 8
Windows Phone Silverlight 8
ASP.NET Core 1.0
Windows Phone 8.1
If you still want to keep the .net 3.5 client target you could provide both in the same nuget package!