Removes versioning from py.exe launcher installer and ensures that old launchers are replaced by newer ones.
diff --git a/Tools/msi/msi.props b/Tools/msi/msi.props
index bbb8aeb..9ae6d99 100644
--- a/Tools/msi/msi.props
+++ b/Tools/msi/msi.props
@@ -39,7 +39,7 @@
     
     <ItemGroup>
         <Compile Include="$(MSBuildThisFileDirectory)common.wxs" />
-        <WxlTemplate Include="$(MSBuildThisFileDirectory)\*.wxl_template" />
+        <WxlTemplate Include="$(MSBuildThisFileDirectory)\*.wxl_template" Condition="$(IgnoreCommonWxlTemplates) != 'true'" />
         <WixExtension Include="WixUtilExtension">
             <HintPath>WixUtilExtension</HintPath>
             <Name>WixUtilExtension</Name>
@@ -150,7 +150,7 @@
             <Uri>lib2to3/pickles</Uri>
         </_Uuid>
     </ItemGroup>
-    <Target Name="_GenerateGuids" AfterTargets="PrepareForBuild">
+    <Target Name="_GenerateGuids" AfterTargets="PrepareForBuild" Condition="$(TargetName) != 'launcher'">
         <PropertyGroup>
             <_Uuids>@(_Uuid->'("%(Identity)", "$(MajorVersionNumber).$(MinorVersionNumber)/%(Uri)")',',')</_Uuids>
             <_GenerateCommand>import uuid; print('\n'.join('{}={}'.format(i, uuid.uuid5(uuid.UUID('c8d9733e-a70c-43ff-ab0c-e26456f11083'), '$(ReleaseUri.Replace(`{arch}`, `$(ArchName)`))' + j)) for i,j in [$(_Uuids.Replace(`"`,`'`))]))</_GenerateCommand>