title: DocumentFormat.OpenXml 2.5 in .NET 3.5.1 gives warnings
body: <p>I have decided to use <code>.NET 3.5.1</code> but when I add the <code>DocumentFormat.OpenXml 2.5</code> throught the NuGet Package Console with Install-Package DocumentFormat.OpenXml I get a lot of warnings : </p>
  
  <blockquote>
    <p>1>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5):
    warning MSB3258: The primary reference "DocumentFormat.OpenXml,
    Version=2.5.5631.0, Culture=neutral, PublicKeyToken=123,
    processorArchitecture=MSIL" could not be resolved because it has an
    indirect dependency on the .NET Framework assembly
    "System.Data.SqlXml, Version=4.0.0.0, Culture=neutral,
    PublicKeyToken=123" which has a higher version "4.0.0.0" than the
    version "2.0.0.0" in the current target framework.</p>
    
    <p>1>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5):
    warning MSB3258: The primary reference "DocumentFormat.OpenXml,
    Version=2.5.5631.0, Culture=neutral, PublicKeyToken=123,
    processorArchitecture=MSIL" could not be resolved because it has an
    indirect dependency on the .NET Framework assembly "System.Security,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=123" which has a
    higher version "4.0.0.0" than the version "2.0.0.0" in the current
    target framework.</p>
    
    <p>1>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5):
    warning MSB3268: The primary reference "DocumentFormat.OpenXml,
    Version=2.5.5631.0, Culture=neutral, PublicKeyToken=123,
    processorArchitecture=MSIL" could not be resolved because it has an
    indirect dependency on the framework assembly "System.Xaml,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=123" which could not
    be resolved in the currently targeted framework.
    ".NETFramework,Version=v3.5". To resolve this problem, either remove
    the reference "DocumentFormat.OpenXml, Version=2.5.5631.0,
    Culture=neutral, PublicKeyToken=123, processorArchitecture=MSIL" or
    retarget your application to a framework version which contains
    "System.Xaml, Version=4.0.0.0, Culture=neutral,
    PublicKeyToken=b77a5c561934e089".</p>
    
    <p>1>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5):
    warning MSB3258: The primary reference "DocumentFormat.OpenXml,
    Version=2.5.5631.0, Culture=neutral, PublicKeyToken=123,
    processorArchitecture=MSIL" could not be resolved because it has an
    indirect dependency on the .NET Framework assembly "Accessibility,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=123" which has a
    higher version "4.0.0.0" than the version "2.0.0.0" in the current
    target framework.</p>
    
    <p>1>C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1605,5):
    warning MSB3268: The primary reference "DocumentFormat.OpenXml,
    Version=2.5.5631.0, Culture=neutral, PublicKeyToken=123,
    processorArchitecture=MSIL" could not be resolved because it has an
    indirect dependency on the framework assembly "System.Numerics,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=123" which could not
    be resolved in the currently targeted framework.
    ".NETFramework,Version=v3.5". To resolve this problem, either remove
    the reference "DocumentFormat.OpenXml, Version=2.5.5631.0,
    Culture=neutral, PublicKeyToken=123, processorArchitecture=MSIL" or
    retarget your application to a framework version which contains
    "System.Numerics, Version=4.0.0.0, Culture=neutral,
    PublicKeyToken=123".</p>
  </blockquote>
  
  <p>It seems like <code>DocumentFormat.OpenXml 2.5</code> needs or is using <code>.Net 4</code>.</p>
  
  <p>Should I worry about these warnings [and stick to <code>.net 4.5</code> where I don't get these warnings]?</p>
  
  <p>I want to avoid <code>.net 4.5</code> since they need admin rights to be installed.</p>