v0.4.7

Viewer changes

• Fix sequential PNGs to have superfluous animation name.
• Be able to export as sequential JPGs.
• Reduce burden on CPU when Spine is yet to be loaded.
  • Call GetMessage and BeginPaint on idle state, and switch to PeekMessage and GPU rendering on loaded.

Build changes

• Use Spine generic runtimes as static library.
  • There is no occasion to modify them, except extensions.cpp/h, in terms of their license conditions.
  • Source files are kept for the sake of IntelliSense and debugging.
• Use pre-compiled header to reduce compile time.