CoreAnimationBook samples, unified upgrade

CoreAnimation samples: BackgroundFilteredView, CustomAnimationTiming,
CustomizeAnimation, CustomizeAnimation2, FilteredView, GroupAnimation,
KeyFrameMoveAView, LayeredBackedControls, QCBackground, and
TimedAnimation.

Corrected compilation errors. However, CustomAnimationTiming,
CustomAnimation, CustomAnimation2, and QCBackground all have runtime
errors, noted in Xamarin-Mac-Unified-Notes.
CoreTextArcMonoMac, CoreWLANWirelessMnager unified

Upgraded and fixed errors. Still have multiple runtime errors in
CoreTextArcMonoMac, described in Xamarin-Mac-Unified-Notes.txt.