Added different in and out easing, deactivateOnComplete and destroyOnComplete options, multiple material alpha blending

- **Cleaned** code by reformatting
- **Added** deactivateOnComplete option *(bool)*
- **Added** destroyOnComplete option *(bool)*
- **Added** the possibility of adding different out and in eases
- **Added** alpha blending on multiple materials
- **Fixed** easeInOutBack being easeInOutElastic