Move some CI stuff out of .travis.yml and into bin/run-travis.
Avoid running sauce tests when part of another project's Travis build.
Travis fix.
Hmm, would have been nice if haxelib dev installed dependencies.
Hint that HTML5 canvas content is opaque for better performance.

http://wiki.whatwg.org/wiki/CanvasOpaque
Added check for negative return values on script Actions that depend on Tween.
Tween could finish in different frame with different delta time so overtime can be bigger than this frame's delta time. Negative return value would cause action not to end and next update it would create another tween.
Added elastic easing

Adapted from
https://github.com/HaxeFlixel/flixel/blob/dev/flixel/tweens/FlxEase.hx
Change (2 * Math.PI) to a cached inline value
Merge pull request #249 from anissen/elastic-easing

Added elastic easing
Merge pull request #247 from Antriel/master

Added check for negative return values on script Actions that depend on Tween
Merge remote-tracking branch 'upstream/master'