title: Attempting to add an MQTT library from NuGet into Xamarin project
body: <p>I saw that Xamarin was now free and decided to try writing a mobile app using it instead of what another technology I was playing with.  After some various hiccups, I was able to get the new Xamarin Android project to build, deploy and run on the simulator.  I then decided to try out MQTT connectivity from it before I went any further.  No matter which MQTT library I to install from NuGet, for example the System.Net.Mqtt one from Xamarin, I get the following error:</p>
  
  <p>"Could not install package 'System.Net.Mqtt 0.3.12-pre'. You are trying to install this package into a project that targets 'MonoAndroid,Version=v6.0', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author."</p>
  
  <p>I tried several others with no success. It does the same for the ios and Android projects.  I did try changing the Android SDK version to use for compiling, but still had the same result.  I also don't understand why it says MonoAndroid since I thought all the Mono references were changed to Xamarin?  I'm using Visual Studio 15 with Update 2.  I tried the stable Xamarin version and also tried the latest alpha.  I'm not sure what else to try, I'd really to give Xamarin a try for this project.  I did some searching and couldn't find anything that appeared to help with this issue.</p>
  
  <p>Thanks in advance for any help.</p>