Switch ReactiveUI to Profile259 which includes WPA81
Retarget the WinRT projects to include WPA81.
Also Testing.
Update Orientation.
iOS refenreces.
In line.
Fix some references.
Simplify the WinMetadata includes.
Fix missing references.
Add Events_WPA81 and Events_WP81.
Events_WinRT only targets Windows 8.1
Remove wrong and unneeded reference.
Add ReactiveUi.Platforms for WP81 Silverlight.
Add binding support for NSMenuItem
Fix Mac build
Fix dependency properties on WinRT by using current.
Merge pull request #621 from reactiveui/dep-prop-current

Fix dependency properties on WinRT by using current.
Merge remote-tracking branch 'origin/rxui6-master' into wpa81

Conflicts:
	Playground-Android/Resources/Resource.designer.cs
	ReactiveUI.Tests/Resources/Resource.designer.cs
Update Splat to 1.3.1 final
Update build paths