[c# grpc] Include grpc generated files automatically

* Two cases need to be handeled: $BondOptions contains --grpc for
  no-overridden BondCodegen items, the %BondCodegen.Options contains
  --grpc. Also --grpc=false needs to be handled in both cases.
* Updated the examples ad tests to no longer include the
  generated *_grpc.cs files.

Fixes #448
Closes #630

CHANGELOG.md

@@ -60,6 +60,18 @@ different versioning scheme, following the Haskell community's
 
 ### C# ###
 
+* **Breaking change** The code generation MSBuild targets no longer support
+  Mono's xbuild: only MSBuild is supported. Mono has
+  [deprecated xbuild in favor MSBuild](http://www.mono-project.com/docs/about-mono/releases/5.0.0/#msbuild)
+  now that
+  [MSBuild is open source and cross-platform](https://github.com/Microsoft/msbuild).
+  These are the MSBuild targets that run `gbc` on `BondCodegen` items.
+* **Breaking change** The code generation MSBuild targets now automatically
+  compile the generated `_grpc.cs` files if `--grpc` is passed to `gbc`.
+  Explicit `<Compile Include="$(IntermediateOutputPath)foo_grpc.cs" />`
+  lines in MSBuild projects will need to be removed to fix error MSB3105
+  about duplicate items. See commit TBD for an example of how to fix this.
+  [Issue #448](https://github.com/Microsoft/bond/issues/448)
 * Added `Bond.Box.Create` helper method to create `Bond.Box<T>` instances.
 * Reflection.IsBonded now recognizes custom IBonded implementations.
 * Use Newtonsoft's JSON.NET BigInteger support -- when available -- to

cs/build/nuget/Common.targets

@@ -127,6 +127,18 @@
         <DependentUpon>%(BondCodegen.Identity)</DependentUpon>
       </_BondGeneratedFiles>
 
+      <_BondGeneratedFiles Include="@(_BondCodegenWithDefaultOptions -> '$(BondOutputDirectory)\%(FileName)_grpc.cs')"
+                           Condition="$(BondOptions.Contains('--grpc')) AND !$(BondOptions.Contains('--grpc=false'))">
+        <AutoGen>true</AutoGen>
+        <DependentUpon>%(BondCodegen.Identity)</DependentUpon>
+      </_BondGeneratedFiles>
+
+      <_BondGeneratedFiles Include="@(BondCodegen -> '$(BondOutputDirectory)\%(FileName)_grpc.cs')"
+                           Condition="$([System.String]::new('%(BondCodegen.Options)').Contains('--grpc')) AND !$([System.String]::new('%(BondCodegen.Options)').Contains('--grpc=false'))">
+        <AutoGen>true</AutoGen>
+        <DependentUpon>%(BondCodegen.Identity)</DependentUpon>
+      </_BondGeneratedFiles>
+
       <_BondGeneratedFileNames Include="@(_BondGeneratedFiles)"/>
       <Compile Include="@(_BondGeneratedFileNames)" />
 

cs/test/compat/grpc/shared/GrpcCompatShared.csproj

@@ -20,13 +20,13 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="$(IntermediateOutputPath)\pingpong_grpc.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <BondCodegen Include="..\..\..\..\..\test\compat\grpc\pingpong.bond">
       <Options>--grpc</Options>
     </BondCodegen>
     <!-- Resharper Workaround -->
     <Compile Include="$(IntermediateOutputPath)\pingpong_types.cs" Condition="False" />
+    <Compile Include="$(IntermediateOutputPath)\pingpong_grpc.cs" Condition="False" />
     <!-- End Resharper Workaround -->
   </ItemGroup>
   <ItemGroup>

examples/cs/grpc/pingpong/grpc_pingpong.csproj

@@ -46,9 +46,8 @@
     </BondCodegen>
     <!-- Resharper Workaround -->
     <Compile Include="$(IntermediateOutputPath)\pingpong_types.cs" Condition="False" />
+    <Compile Include="$(IntermediateOutputPath)\pingpong_grpc.cs" Condition="False" />
     <!-- End Resharper Workaround -->
-    <!-- TODO: edit the .targets to automatically include the grpc files -->
-    <Compile Include="$(IntermediateOutputPath)\pingpong_grpc.cs" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="Attributes">

examples/cs/grpc/scalar/grpc_scalar.csproj

@@ -51,9 +51,8 @@
     </BondCodegen>
     <!-- Resharper Workaround -->
     <Compile Include="$(IntermediateOutputPath)\scalar_types.cs" Condition="False" />
+    <Compile Include="$(IntermediateOutputPath)\scalar_grpc.cs" Condition="False" />
     <!-- End Resharper Workaround -->
-    <!-- TODO: edit the .targets to automatically include the grpc files -->
-    <Compile Include="$(IntermediateOutputPath)\scalar_grpc.cs" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="Attributes">