Obsolete API (#1686)

* Make most things in Microsoft.ML.Legacy assembly obsolete

* Resolve complier warnings by
1. Disable warning 612 reported in test file
2. Remove Microsoft.ML.PipelineInference project
3. Remove two commands used in pipeline inference.
   - InferRecipesCommand.cs
   - InferSchemaCommand.cs
Note that we add [Obsolete] to everything in Microsoft.ML.Legacy but auto-generated APIs.

* More obsolete things.
1. Make everything in CSharpApi.cs obsolete by modifying CSharpApiGenerator.cs
   and CSharpGeneratorUtils.cs.
2. Some checked-in [Obsolete] are removed because they conflict with those
   automatically generated in CSharpApi.cs.
3. Some classes in Microsoft.ML.Legacy are still not obsolete so we addd
   [Obsolete] to them.
4. Supress warnings 612 and 618 (warning 44 for F# test) for tests and benchmarks.

* Minor cleaning

* Not to load PipelineInference because it no longer exists

* New strategy for marking things obsolete
1. Things in Microsoft.ML.Legacy.Runtime are not obsolete. If they
   reference to obsolete CSharpApi.cs, we supress the warning 612.
2. Things in Microsoft.ML.Legacy have two destinies. Anything
    (a) referring CSharpApi.c,
    (b) being a part of CSharpApi.cs, or
    (c) using ILearningPipelineItem.cs
    are are obsolete. Otherwise, they are not obsolete.

* Update CSharpApi.cs again because rebuilding didn't remove the deleted project's binary files

* Address comments

Author: wschin

Microsoft.ML.sln

@@ -15,8 +15,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.ML.Core.Tests", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.ML.CpuMath", "src\Microsoft.ML.CpuMath\Microsoft.ML.CpuMath.csproj", "{46F2F967-C23F-4076-858D-33F7DA9BD2DA}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.ML.PipelineInference", "src\Microsoft.ML.PipelineInference\Microsoft.ML.PipelineInference.csproj", "{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.ML.Data", "src\Microsoft.ML.Data\Microsoft.ML.Data.csproj", "{AD92D96B-0E96-4F22-8DCE-892E13B1F282}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.ML.Onnx", "src\Microsoft.ML.Onnx\Microsoft.ML.Onnx.csproj", "{65D0603E-B96C-4DFC-BDD1-705891B88C18}"
@@ -165,14 +163,6 @@ Global
 		{46F2F967-C23F-4076-858D-33F7DA9BD2DA}.Release|Any CPU.Build.0 = Release|Any CPU
 		{46F2F967-C23F-4076-858D-33F7DA9BD2DA}.Release-Intrinsics|Any CPU.ActiveCfg = Release-Intrinsics|Any CPU
 		{46F2F967-C23F-4076-858D-33F7DA9BD2DA}.Release-Intrinsics|Any CPU.Build.0 = Release-Intrinsics|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Debug-Intrinsics|Any CPU.ActiveCfg = Debug-Intrinsics|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Debug-Intrinsics|Any CPU.Build.0 = Debug-Intrinsics|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Release|Any CPU.Build.0 = Release|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Release-Intrinsics|Any CPU.ActiveCfg = Release-Intrinsics|Any CPU
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44}.Release-Intrinsics|Any CPU.Build.0 = Release-Intrinsics|Any CPU
 		{AD92D96B-0E96-4F22-8DCE-892E13B1F282}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{AD92D96B-0E96-4F22-8DCE-892E13B1F282}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{AD92D96B-0E96-4F22-8DCE-892E13B1F282}.Debug-Intrinsics|Any CPU.ActiveCfg = Debug-Intrinsics|Any CPU
@@ -509,7 +499,6 @@ Global
 		{A6CA6CC6-5D7C-4D7F-A0F5-35E14B383B0A} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{EC743D1D-7691-43B7-B9B0-5F2F7018A8F6} = {AED9C836-31E3-4F3F-8ABC-929555D3F3C4}
 		{46F2F967-C23F-4076-858D-33F7DA9BD2DA} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
-		{2D7391C9-8254-4B8F-BF26-FADAF8F02F44} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{AD92D96B-0E96-4F22-8DCE-892E13B1F282} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{65D0603E-B96C-4DFC-BDD1-705891B88C18} = {09EADF06-BE25-4228-AB53-95AE3E15B530}
 		{707BB22C-7E5F-497A-8C2F-74578F675705} = {09EADF06-BE25-4228-AB53-95AE3E15B530}

src/Microsoft.ML.Console/Microsoft.ML.Console.csproj

@@ -21,7 +21,6 @@
     <ProjectReference Include="..\Microsoft.ML.OnnxTransform\Microsoft.ML.OnnxTransform.csproj" />
     <ProjectReference Include="..\Microsoft.ML.Onnx\Microsoft.ML.Onnx.csproj" />
     <ProjectReference Include="..\Microsoft.ML.PCA\Microsoft.ML.PCA.csproj" />
-    <ProjectReference Include="..\Microsoft.ML.PipelineInference\Microsoft.ML.PipelineInference.csproj" />
     <ProjectReference Include="..\Microsoft.ML.Recommender\Microsoft.ML.Recommender.csproj" />
     <ProjectReference Include="..\Microsoft.ML.ResultProcessor\Microsoft.ML.ResultProcessor.csproj" />
     <ProjectReference Include="..\Microsoft.ML.StandardLearners\Microsoft.ML.StandardLearners.csproj" />

src/Microsoft.ML.Legacy/AssemblyRegistration.cs

@@ -51,14 +51,6 @@ private static bool LoadStandardAssemblies()
             _ = typeof(OneHotEncodingTransformer).Assembly; // ML.Transforms
 
             // The following assemblies reference this assembly, so we can't directly reference them
-
-            //_ = typeof(Microsoft.ML.Runtime.PipelineInference.AutoInference).Assembly); // ML.PipelineInference
-            _ = Assembly.Load(new AssemblyName()
-            {
-                Name = "Microsoft.ML.PipelineInference",
-                Version = apiAssemblyName.Version, //assume the same version as ML.Api
-            });
-
             //_ = typeof(Microsoft.ML.Runtime.Data.LinearPredictor).Assembly); // ML.StandardLearners
             _ = Assembly.Load(new AssemblyName()
             {