Correct worker dependency

Now have very crude implementation of discovery that doesn't use shadow
copying and doesn't lock DLLs in memory.  TONS of work to be done here
but beginning to get the basic pattern.

First step in resolving #4

xunit.runner.wpf/xunit.runner.wpf.csproj

@@ -151,6 +151,10 @@
       <Project>{a1f579f4-443e-4f64-bc55-998ab86ff293}</Project>
       <Name>xunit.runner.data</Name>
     </ProjectReference>
+    <ProjectReference Include="..\xunit.runner.worker\xunit.runner.worker.csproj">
+      <Project>{9df97a2b-0eb5-4b12-9f81-69dfac979814}</Project>
+      <Name>xunit.runner.worker</Name>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.