ENYO-373: Add option to bypass adding control to roots.

### Issue
There are situations where we do not wish to add a control to the view roots.

### Fix
We added a parameter, `preventRooting`, to `enyo.Control`'s `renderInto` method that allows for the prevention of adding a control to the view roots.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>