[WIP] Overhauled project to make Linux build work out of the box

TODO: fix the Windows build, fix the Debug builds, make OSX
configurations, work around a bug in MonoDevelop where copied content
files don't respect the original directory structure

NuGet.Config

@@ -7,6 +7,6 @@
     <add key="Microsoft and .NET" value="true" />
   </disabledPackageSources>
   <config>
-    <add key="repositoryPath" value=".\Libraries\NuGet" />
+    <add key="repositoryPath" value="Libraries/NuGet" />
   </config>
 </configuration>