Provide skeleton DllGetClassObject and DllCanUnloadNow implementations.

src/windows/com/comentrypoints.c

+/*
+ * Copyright (C) 2016 Reece H. Dunn
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see: <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <windows.h>
+
+HRESULT __stdcall DllGetClassObject(REFCLSID classId, REFIID iface, void **pObject)
+{
+	if (!pObject)
+		return E_POINTER;
+
+	*pObject = NULL;
+	return CLASS_E_CLASSNOTAVAILABLE;
+}
+
+HRESULT __stdcall DllCanUnloadNow(void)
+{
+	return S_OK;
+}

src/windows/libespeak-ng.def

+LIBRARY
+EXPORTS
+	DllCanUnloadNow          PRIVATE
+	DllGetClassObject        PRIVATE

src/windows/libespeak-ng.vcxproj

     <Link>
       <SubSystem>Windows</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ModuleDefinitionFile>libespeak-ng.def</ModuleDefinitionFile>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <Link>
       <SubSystem>Windows</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ModuleDefinitionFile>libespeak-ng.def</ModuleDefinitionFile>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ModuleDefinitionFile>libespeak-ng.def</ModuleDefinitionFile>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ModuleDefinitionFile>libespeak-ng.def</ModuleDefinitionFile>
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="..\libespeak-ng\tr_languages.c" />
     <ClCompile Include="..\libespeak-ng\voices.c" />
     <ClCompile Include="..\libespeak-ng\wavegen.c" />
+    <ClCompile Include="com\comentrypoints.c" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\include\espeak-ng\espeak_ng.h" />
     <ClInclude Include="..\libespeak-ng\voice.h" />
     <ClInclude Include="config.h" />
   </ItemGroup>
+  <ItemGroup>
+    <None Include="libespeak-ng.def" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>

src/windows/libespeak-ng.vcxproj.filters

     <Filter Include="Header Files\api">
       <UniqueIdentifier>{7bec9d7b-17d5-4ff3-b0c8-0b6f746548a3}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Source Files\com">
+      <UniqueIdentifier>{77d943b9-0670-4e38-b6ad-592ad6c85094}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\libespeak-ng\compiledata.c">
     <ClCompile Include="..\libespeak-ng\mbrowrap.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="com\comentrypoints.c">
+      <Filter>Source Files\com</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="config.h">
       <Filter>Header Files</Filter>
     </ClInclude>
   </ItemGroup>
+  <ItemGroup>
+    <None Include="libespeak-ng.def">
+      <Filter>Source Files</Filter>
+    </None>
+  </ItemGroup>
 </Project>