Enyo 1875: added preview reload b

* ENYO-1875: added reload icon (HEAD, origin/ENYO-1875, ENYO-1875)
* ENYO-1875: added reload button
* ENYO-1875: preview now keeps track of current zoom factor
* ENYO-1875: added reload method
* ENYO-1875: Move device picker in its own kind to reduce indent depth
* -added groupbox around device and orientation buttons
* ENYO-1875: fix missing gray groupbox line around slider

Enyo-DCO-1.1-Signed-off-by: Dominique Dumont <dominique.dumont@hp.com>