Build against CLR 4 to support PowerShell V3

Author: lzybkr

PSReadLine/PSReadLine.csproj

@@ -9,9 +9,9 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>PSReadLine</RootNamespace>
     <AssemblyName>Microsoft.PowerShell.PSReadLine</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
-    <TargetFrameworkProfile></TargetFrameworkProfile>
+    <TargetFrameworkProfile>Client</TargetFrameworkProfile>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>