Attached properties not fully supported in dependency property factory #13
Description
I'm extending the support for creating dependency properties through the dependency property factory (DP factory), including allowing to set AffectsMeasure, etc .. in FrameworkElementMetaData.
However, since the DP factory requires attributes to be placed on a get and set method for attached properties, the way to implement attached properties is starting to deviate more and more from normal properties.
Possibly support for attached properties should be removed entirely, or a better way to support them should be found.