Merge remote-tracking branch 'origin/master' into new-rxui6-master

Conflicts:
	NuGet/ReactiveUI-Platforms/ReactiveUI-Platforms.nuspec
Merge branch 'new-use-splat' into new-rxui6-master

Conflicts:
	ReactiveUI.Platforms/Xaml/RoutedViewHost.cs
Upgrade to Windows 8.1
Check in Win8.1 metadata
Fix building Events library on WinRT
Fixups from merge tragedy
Update bad version of Splat.dll
Fix up bad references