ENYO-2775: use overlays for less & add non-reg unit test

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>
Merge branch 'ENYO-2775' of github.com:enyojs/ares-project into ENYO-2775

# By Francois-Xavier Kowalski
# Via Francois-Xavier Kowalski
* 'ENYO-2775' of github.com:enyojs/ares-project:
  ENYO-2775: fix console error on IE10