Update fx.js
Update fx.js

Fix a bug in which we could not chain animations.
shelsonjava/philogl,philogb/philogl,shelsonjava/philogl,printedheart/philogl,printedheart/philogl,philogb/philogl,philogb/philogl,shelsonjava/philogl,shelsonjava/philogl,printedheart/philogl