Bug 888184 - Remove the canvas-based animations introduced in the workaround for bug 822345

- Removed the JavaScript code used to create the animations
- Replace the animated canvases with APNG animtions
- Removed the unused PNG files and recompressed the existing ones
Merge pull request #10724 from gabrielesvelto/bug-888184

Bug 888184 - Remove the canvas-based animations introduced in the workaround for bug 822345 r=alive