ENYO-3282: add button restore defaults to code editor settings 

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3282

Tested on W7, IE10, FF, Chrome.

In this PR, a small css regression on alignement of the radio group inside the popup title was fixed.

Enyo-DCO-1.1-Signed-off-by: Olga Popova <olga.popova@hp.com>