win32: Moved PlatformToolset configuration to individual project files. It should be set before setting other properties or importing other props.

This fixes the broken GUI Platform Toolset indicator, as well as VS compilation itself if another version such as 2010 was also installed.

win32/copy/copy.vcxproj

@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Release|Win32">
       <Configuration>Release</Configuration>