Add HackerNews python plugin as the Demo.

Wox.Plugin/HttpProxy.cs

@@ -0,0 +1,10 @@
+namespace Wox.Plugin
+{
+    public class HttpProxy
+    {
+        public string Address { get; set; }
+        public int Port { get; set; }
+        public string UserName { get; set; }
+        public string Password { get; set; }
+    }
+}

Wox.Plugin/PluginInitContext.cs

@@ -14,6 +14,8 @@ namespace Wox.Plugin
         /// </summary>
         public IPublicAPI API { get; set; }
 
+        public HttpProxy Proxy { get; set; }
+
         #region Legacy APIs
 
         [Obsolete("This method has been obsoleted, use API.ShellRun instead")]

Wox.Plugin/PluginPair.cs

@@ -9,6 +9,5 @@ namespace Wox.Plugin
     {
         public IPlugin Plugin { get; set; }
         public PluginMetadata Metadata { get; set; }
-        public PluginInitContext InitContext { get; set; }
     }
 }

Wox.Plugin/Wox.Plugin.csproj

@@ -45,6 +45,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AllowedLanguage.cs" />
+    <Compile Include="HttpProxy.cs" />
     <Compile Include="IPlugin.cs" />
     <Compile Include="IPublicAPI.cs" />
     <Compile Include="ISettingProvider.cs" />