ENYO-2525: add preview button in code editor
ENYO-2525: change array notation
ENYO-2525: change array-based loop
ENYO-2525: add enyo.forEach loop
ENYO-2525: clarify code reading
ENYO-2525: small cleanup
ENYO-2525: remove unnecessary closures
ENYO-2525: remove useless comment
Merge pull request #493 from enyojs/ENYO-2525

ENYO-2525: add preview button in code editor