Update project platform, add montion player and update sample app.

[Cricle]

Project modify

1. Add platforms netcoreapp3.0 and NET461.
2. Add nuget information and generate pre build. (Please modify and fill in the necessary information before publishing)

   Functions modify

3. Add motion state change event in L2DView.
4. Add MotionPlayer to L2DLib project.
5. Add some extension methods easy to use L2DModel type and view.
6. Making holder can be set BitmapScalingMode.

   Sample modify

7. Add loop menu in motion ListView.
8. Add eyeblink control menu in motion ListView.
9. Add fade in time(1000ms) when model loaded.

The motion player can loop any motion what you want. Useage:

1. Use extension method

   L2DModel.CreatePlayer(view,key).Begin();

   It will loop designated motion group.

2. Use constructor

   new MotionPlayer(view,anymotions).Begin();

   It will loop what your favorite combination.

And then you can delay any time when some motion done!

//Set property
Func<L2DMotion,TimeSpan> DelayFactory

If want to once or forever loop

//Set this property false or true
MotionPlayer.Loop

[iodes]

That's a great job! Thank you.