! fixed a bug in timeline preventing some tweens to start under speci… …al condition, ! fixed a bug in setCallback which reset the triggers to 'complete'

* updated build script 

* updated version to 6.3.1 

* changed build.xml to add sources to demo zip 

+ (demo) added an 'info' test 

* updated build script 

* merged TweenManager.add() methhods into one, ! fixed a bug preventing targets implementing TweenAccessor from being used

! fixed build script 

* changed returned arrays into lists in some TweenManager methods 

+ added callbacks for backwards events, + added a Tween.mark() static method (see javadoc), * reduced the size footprint of every tween, * updated the demo with speed control, * updated javadoc