Minor edits of the contribution checklist documentation.
Add Animatable class.
Add attribute animation.
Add attribute animation sample in StaticScene.
Refactor AttributeAnimation.
Add object animation, add load and save functions.
Add missing header file.
Refactor animation system, add AttributeAnimationInstance.
Ignore network update when update animations.
Remove ignore network update, add animated network attribute check.
Remove child object animation, add load and save function.
Save event frame to xml, Remove binary load and save function in animation classes.
Save enum type with string.
Add resource load and save functions for animations.
Add get Lua attribute name in C++, not finish.[ci skip]
Minor fixed.
Add Lua object attribute set and get function.
Add template variant.
Add animation Lua API.
Add Angelscript API.