Facade interval (Animation time step) from ScrollMath to TouchScrollStrategy.

Enyo-DCO-1.1-Signed-off-by: Kunmyon Choi <kunmyon.choi@lge.com>
Adding intervalChanged to create so that it can set initial value.

Enyo-DCO-1.1-Signed-off-by: Kunmyon Choi <kunmyon.choi@lge.com>
Merge pull request #444 from enyojs/facadeOnTouchScrollStrategy-kunmyonchoi

Facade interval (Animation time step) from ScrollMath to TouchScrollStra...

Reviewed-By: Cole Davis (cole.davis@lge.com)