Fixes ENYO-696

## Issue
Occasionally, marquee text that can fit within its container will animate 1px unnecessarily. This appears to be due to a rounding difference between scrollWidth and clientWidth for sub-pixel precision values which results in a 1px marquee distance.

## Fix
Use `getClientBoundingRect()` for marquee distance calculation

Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)