File's sorting Directories before Files

*Fix #249
Progress bar, progress fix

* use Node's methods
* Fix #247
Remove root Node in fileexplorer with toolbar

* Fix #245
+root still present if fileexplorer instanciated without toolbar
Merge branch 'master' of github.com:Heigvd/Wegas

# By Francois-Xavier Aeberhard (5) and Anthony Geiser (1)
# Via Anthony Geiser (1) and Francois-Xavier Aeberhard (1)
* 'master' of github.com:Heigvd/Wegas:
  Fix #135
  Fix not found game error in GameController
  Fix issues in CEP game
  Add loading overlay to console
  Refactor wegas-panelwidget to wegas-layout-panel
  Update default values