ENYO-431: Run detectAlignment when content changes, only when generated.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
Merge pull request #1746 from enyojs/ENYO-431-aarontam

ENYO-431: Run detectAlignment when content changes, only when generated.

Reviewed-by: Ryan Duffy (ryan.duffy@lge.com)
Integrated-by: Cole Davis (cole.davis@lge.com)