#7 - Rework platform abstractions for .netcore to allow windowsauth module

Author: eByte23

Source/MySql.Data/Authentication/AuthenticationManager.cs

@@ -36,17 +36,19 @@ static AuthenticationPluginManager()
       {
         plugins["mysql_native_password"] = new PluginInfo("MySql.Data.MySqlClient.Authentication.MySqlNativePasswordPlugin");
         plugins["sha256_password"] = new PluginInfo("MySql.Data.MySqlClient.Authentication.Sha256AuthenticationPlugin");
-#if !CF && !RT && !NETSTANDARD1_3
+#if !CF && !RT
         plugins["authentication_windows_client"] = new PluginInfo("MySql.Data.MySqlClient.Authentication.MySqlWindowsAuthenticationPlugin");
+#if !NETSTANDARD1_3
         if (MySqlConfiguration.Settings != null && MySqlConfiguration.Settings.AuthenticationPlugins != null)
         {
           foreach (AuthenticationPluginConfigurationElement e in MySqlConfiguration.Settings.AuthenticationPlugins)
             plugins[e.Name] = new PluginInfo(e.Type);
         }
 #endif
-      }
+#endif
+        }
 
-      public static MySqlAuthenticationPlugin GetPlugin(string method)
+        public static MySqlAuthenticationPlugin GetPlugin(string method)
       {
         if (!plugins.ContainsKey(method))
           throw new MySqlException(String.Format(Resources.AuthenticationMethodNotSupported, method));

Source/MySql.Data/Authentication/WindowsAuthenticationPlugin.cs

@@ -47,11 +47,10 @@ internal class MySqlWindowsAuthenticationPlugin : MySqlAuthenticationPlugin
     protected override void CheckConstraints()
     {
       string platform = String.Empty;
-#if !RT && !NETSTANDARD1_3
-      int p = (int)Environment.OSVersion.Platform;
-      if ((p == 4) || (p == 128))
+#if !RT
+     if(RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
         platform = "Unix";
-      else if (Environment.OSVersion.Platform == PlatformID.MacOSX) 
+      else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX)) 
         platform = "Mac OS/X";
 
       if (!String.IsNullOrEmpty(platform))