ANG-2680: Allow for multiple, consecutive spaces in MarqueeItem.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
ANG-2680: Added white-space setting to .moon-marquee-text as well (was not inherited).  Update Header, Button, and Item sample to demonstrate use of extra spaces.  Fix bad-practice component naming in ButtonSample while we're at it.
DCO-1.1-Signed-Off-By: Kevin Schaaf <kevin.schaaf@lge.com>
Merge pull request #1177 from enyojs/ANG-2680-aarontam-2

ANG-2680: Allow for multiple, consecutive spaces in MarqueeItem.