Update solution to VS2013 (12.0)

Author: Marek Kulik

sockets/ml_sockets.vcxproj

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -26,25 +26,25 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v120</PlatformToolset>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v120</PlatformToolset>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v120</PlatformToolset>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v120</PlatformToolset>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>