Add missing Ninject and FluentAssertions packages
Enable building with VS2010/.NET40 and fix NuGet restore

- Revert framework reference from v4.5 to v4.0
- Remove app.config files
- Remove all package files, instead rely on NuGet to download them
- Correct dependent Newtonsoft.Json package reference to version 4.0.8
- Add missing references to ReactiveUI and Rx-Compat_Unofficial
- Keep a copy of ReactiveUI.Xaml.dll under packages-mod that was found to
  be different to the NuGet distributed version 3.0.1
Fix building with VS2010/.NET40 even on non-.NET45 machines, use latest RxUI 3.2.0
Merge pull request #1 from PKRoma/pk/vs2012

Enable building with VS2010/.NET40 and fix NuGet restore