Support .NET Framework 4.6.1 (#60)

* support .NET Framework 461

* change ":" to "-" in CarrierItem

src/SkyWalking.Abstractions/Context/CarrierItem.cs

@@ -64,7 +64,7 @@ namespace SkyWalking.Context
             }
             else
             {
-                _headKey = $"{AgentConfig.Namespace}:{headKey}";
+                _headKey = $"{AgentConfig.Namespace}-{headKey}";
             }
             _headValue = headValue;
             _next = next;

src/SkyWalking.Abstractions/SkyWalking.Abstractions.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>SkyWalking Core abstractions and interfaces for apm agent.</Description>
     <AssemblyTitle>SkyWalking.Abstractions</AssemblyTitle>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <AssemblyName>SkyWalking.Abstractions</AssemblyName>
     <PackageId>SkyWalking.Abstractions</PackageId>
     <PackageTags>SkyWalking;APM</PackageTags>

src/SkyWalking.Core/SkyWalking.Core.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>SkyWalking core components.</Description>
     <AssemblyTitle>SkyWalking.Core</AssemblyTitle>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <AssemblyName>SkyWalking.Core</AssemblyName>
     <PackageId>SkyWalking.Core</PackageId>
     <PackageTags>SkyWalking;APM</PackageTags>
@@ -18,5 +18,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.4.1" />
+    <PackageReference Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.3.0" />
+    <PackageReference Include="System.ValueTuple" Version="4.5.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.NetworkProtocol.Trace/SkyWalking.NetworkProtocol.Trace.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>SkyWalking trace protocol.</Description>
     <AssemblyTitle>SkyWalking.NetworkProtocol.Trace</AssemblyTitle>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <AssemblyName>SkyWalking.NetworkProtocol.Trace</AssemblyName>
     <PackageId>SkyWalking.NetworkProtocol.Trace</PackageId>
     <PackageTags>SkyWalking</PackageTags>

src/SkyWalking.NetworkProtocol/SkyWalking.NetworkProtocol.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>SkyWalking gRPC protocol and generated codes.</Description>
     <AssemblyTitle>SkyWalking.NetworkProtocol</AssemblyTitle>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <AssemblyName>SkyWalking.NetworkProtocol</AssemblyName>
     <PackageId>SkyWalking.NetworkProtocol</PackageId>
     <PackageTags>SkyWalking</PackageTags>