v0.5.1 - Gridded Loins

This release is mostly bugfixes for issues I've been encountering while putting the Sokoban example together, but there is one minor feature: The scene editor now has a grid toggle, and objects will snap to the grid when it is visible. This makes it much easier to align things for tile-based games.

The full list of fixes:

• Fix reactivity in entity properties
• Fix entity drag/drop in game not updating entity data in scene panel
• Fix entity selection in game not showing entity properties in panel
• Fix texture bleeding in texture atlases
• Fix entities not appearing right away in editor
• Fix creating new scene throws errors
• Fix cannot change entity name
• Fix duplicate entity menu option broken