cleanup some logic in TouchScroller and ScrollMath to ensure they are reacting as expected, better guard scroll handling in VerticalDelegate

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
appease jshintlord

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
remove unnecessary comment

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
Merge pull request #694 from enyojs/ENYO-3899-coledavis

Fix for ENYO-3899

Reviewed-By: Ben Combee (ben.combee@lge.com)