The End is Nigh: Editor Update v1.0.21

Version Changelog:

- Fixed a crash when selecting "Cancel and Exit" on the Preferences menu.
- Fixed a spelling mistake on the Preferences menu discard changes popup prompt.
- Fixed previous level's undo history persisting when using the load next/previous level feature.
- Fixed the "Changelog" button on the About page going to an invalid web address.
- The about page now displays whether the current build is 32-bit or 64-bit.