Add flingBezier, bounceBezier, flingTruncatedBezier and decelerateBezier instance options
Merge branch 'feature-expose-bezier' of git://github.com/joshfire/ftscroller into joshfire-feature-expose-bezier, reworking variable definitions and merging flingBezier and truncatedFlingBezier into a single definition
Update the readme to document the new bezier curve options