Add Tizen backend

src/ReactiveUI/Platforms/tizen/PlatformRegistrations.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MS-PL license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace ReactiveUI
+{
+    public class PlatformRegistrations : IWantsToRegisterStuff
+    {
+        public void Register(Action<Func<object>, Type> registerFunction)
+        {
+            throw new Exception("You are referencing the Portable version of ReactiveUI in an App. Reference the platform-specific version.");
+        }
+    }
+}

src/ReactiveUI/ReactiveUI.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard1.1;net45;uap10.0;Xamarin.iOS10;Xamarin.Mac20;MonoAndroid80;netcoreapp1.0</TargetFrameworks>
+    <TargetFrameworks>netstandard1.1;net45;uap10.0;Xamarin.iOS10;Xamarin.Mac20;MonoAndroid80;netcoreapp1.0;tizen40</TargetFrameworks>
     <AssemblyName>ReactiveUI</AssemblyName>
     <RootNamespace>ReactiveUI</RootNamespace>
     <Description>A MVVM framework that integrates with the Reactive Extensions for .NET to create elegant, testable User Interfaces that run on any mobile or desktop platform. Supports Xamarin.iOS, Xamarin.Android, Xamarin.Mac, Xamarin Forms, WPF, Windows Forms, Windows Phone 8.1, Windows Store and Universal Windows Platform (UWP).</Description>
@@ -62,6 +62,11 @@
     <PackageReference Include="System.Dynamic.Runtime" Version="4.3.0" />
     <PackageReference Include="System.Runtime.Serialization.Primitives" Version="4.3.0" />
   </ItemGroup>
+
+  <ItemGroup Condition=" '$(TargetFramework)' == 'tizen40' ">
+    <Compile Include="Platforms\tizen\**\*.cs" />
+    <PackageReference Include="Tizen.NET" Version="4.0.0" />
+  </ItemGroup>
 
   <ItemGroup>
     <None Update="VariadicTemplates.tt" Generator="TextTemplatingFileGenerator" LastGenOutput="VariadicTemplates.cs" />