avoid stacking of animations
- with the previous code, clicking twice in a slide before it was in background made it to repeat the animation, and getting extra left-margin
some refactor
- checking if slide is being animated with external function
- making use of "-=" and "+=" syntax of jQuery
preparing pull request
- added minified version
- including myself in authors list
Merge pull request #1 from epaezrubio/master

avoid stacking of animations