MSBuild copy link content over. From http://mattperdeck.com/post/Copying-linked-content-files-at-each-build-using-MSBuild.aspx
<Target Name="CopyLinkedContentFiles" BeforeTargets="Build">
<Copy SourceFiles="%(Content.Identity)"
DestinationFiles="%(Content.Link)"
SkipUnchangedFiles='true'
OverwriteReadOnlyFiles='true'
Condition="'%(Content.Link)' != ''" />
</Target>