Extra extensions (#5)

* Adding MethodInfo.IsExtensionMethod(), .IsImplicitOperator() and .IsExplicitOperator()
Replacing Linq Select and Where with simpler iterators

* Referencing Net40 test files in Net35 test project

* Test coverage for MethodInfo.IsImplcitOperator and .IsExplicitOperator

Author: SteveWilkes

NetStandardPolyfills.UnitTests.Net35/NetStandardPolyfills.UnitTests.Net35.csproj

@@ -44,16 +44,11 @@
     <Compile Include="..\CommonAssemblyInfo.cs">
       <Link>Properties\CommonAssemblyInfo.cs</Link>
     </Compile>
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="WhenCheckingAssemblyData.cs" />
-    <Compile Include="WhenCheckingTypeData.cs" />
-    <Compile Include="WhenRetrievingTypeCodes.cs" />
-    <Compile Include="WhenRetrievingTypeConstructors.cs" />
-    <Compile Include="WhenRetrievingTypeFields.cs" />
-    <Compile Include="WhenRetrievingTypeMembers.cs" />
-    <Compile Include="WhenRetrievingTypeMethods.cs" />
-    <Compile Include="WhenRetrievingTypeOperators.cs" />
-    <Compile Include="WhenRetrievingTypeProperties.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\NetStandardPolyfills.UnitTests.Net40\**\*.cs" Exclude="..\NetStandardPolyfills.UnitTests.Net40\obj\**\*.cs;">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\NetStandardPolyfills.UnitTests\NetStandardPolyfills.UnitTests.csproj">