DispatcherHelper class improved, minor fixes

v2.8.1.0

DispatcherHelper class improved, minor fixes

PointerHelper class and more info APIs added

• PointerHelper class added to quickly manage control pointer states
• Added some APIs to easily detect whether the current device is a phone or a desktop
• Minor fixes

Added XAML custom acrylic brush

Merge pull request #3 from Sergio0694/feature_acrylic_brushes

Feature acrylic brushes

Added light attenuation property, minor refactoring

• Added new SpotLight attenuation property
• Removed the SpotLight alpha property as it was unnecessary
• Minor code refactoring and improvements

Minor fixes

Merge branch 'master' of https://github.com/Sergio0694/UICompositionA…

…nimations

Alpha and shade spot light properties added

Merge branch 'master' of https://github.com/Sergio0694/UICompositionA…

…nimations

Added XAML light effects

• Added custom XAML light brush and effects
• Added helper class to gather APIs info

Added shared CanvasDevice support

• Added the ability to use the shared CanvasDevice instance when creating attached effects

Code stability improvements

• The attached effects can now be created from background threads
• Minor code refactoring

Minor improvements

• Improved the Dispose method for attached effects
• Minor code refactoring