Spriter 2 version 0.7.2 release

[h2]Change Log[/h2]
Additions
- A system for optimizing 2D meshes attached to multiple bones by subdividing them in a way that minimizes vertices in non-deforming areas and maximizes triangles in curved areas, resulting in a smoother bend when the mesh is deformed by bones while also avoiding unnecessary vertices.
- Added keyboard shortcuts (1 and 2) to skip the time to the previous and next keyframes in animation mode