improve project.json files

src/csharp/Grpc.Core.Tests/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.Core/project.json

@@ -22,7 +22,6 @@
     }
   },
   "buildOptions": {
-    "compile": "**/*.cs",
     "embed": [ "../../../etc/roots.pem" ]
   },
   "dependencies": {

src/csharp/Grpc.Dotnet.sln

@@ -29,6 +29,8 @@ Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "Grpc.IntegrationTesting.Qps
 EndProject
 Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "Grpc.IntegrationTesting.Server", "Grpc.IntegrationTesting.Server\Grpc.IntegrationTesting.Server.xproj", "{881F7AD1-A84E-47A2-9402-115C63C4031E}"
 EndProject
+Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "Grpc.IntegrationTesting.StressClient", "Grpc.IntegrationTesting.StressClient\Grpc.IntegrationTesting.StressClient.xproj", "{0EBC910B-8867-4D3E-8686-91F34183D839}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -87,6 +89,10 @@ Global
 		{881F7AD1-A84E-47A2-9402-115C63C4031E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{881F7AD1-A84E-47A2-9402-115C63C4031E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{881F7AD1-A84E-47A2-9402-115C63C4031E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0EBC910B-8867-4D3E-8686-91F34183D839}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0EBC910B-8867-4D3E-8686-91F34183D839}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0EBC910B-8867-4D3E-8686-91F34183D839}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0EBC910B-8867-4D3E-8686-91F34183D839}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/csharp/Grpc.Examples.MathClient/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.Examples.MathServer/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.Examples.Tests/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.Examples/project.json

 {
-  "buildOptions": {
-    "compile": "**/*.cs"
-  },
-
   "dependencies": {
     "Grpc.Core": {
       "target": "project"

src/csharp/Grpc.HealthCheck.Tests/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.HealthCheck/project.json

@@ -12,9 +12,6 @@
     "requireLicenseAcceptance": false,
     "tags": [ "gRPC health check" ]
   },
-  "buildOptions": {
-    "compile": "**/*.cs"
-  },
   "dependencies": {
     "Grpc.Core": "0.14.0-anexperiment",
     "Google.Protobuf": "3.0.0-beta3"

src/csharp/Grpc.IntegrationTesting.Client/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.IntegrationTesting.QpsWorker/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.IntegrationTesting.Server/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.IntegrationTesting.StressClient/Grpc.IntegrationTesting.StressClient.xproj

+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0.25123" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">14.0.25123</VisualStudioVersion>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DotNet\Microsoft.DotNet.Props" Condition="'$(VSToolsPath)' != ''" />
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>0ebc910b-8867-4d3e-8686-91f34183d839</ProjectGuid>
+    <RootNamespace>Grpc.IntegrationTesting.StressClient</RootNamespace>
+    <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">.\obj</BaseIntermediateOutputPath>
+    <OutputPath Condition="'$(OutputPath)'=='' ">.\bin\</OutputPath>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <SchemaVersion>2.0</SchemaVersion>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DotNet\Microsoft.DotNet.targets" Condition="'$(VSToolsPath)' != ''" />
+</Project>
\ No newline at end of file

src/csharp/Grpc.IntegrationTesting.StressClient/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",

src/csharp/Grpc.IntegrationTesting/project.json

 {
   "buildOptions": {
-    "compile": "**/*.cs",
     "copyToOutput": {
       "mappings": {
         "nativelibs/windows_x64/grpc_csharp_ext.dll": "../../../vsprojects/x64/Debug/grpc_csharp_ext.dll",