Add loading overlay for #310
Refactor layout widgets
Refactor layout continued
Refactor on wegas-chart.js
Refactor PMG widgets
Optimize treeview loading
Merge branch 'HEAD' of git@github.com:Heigvd/Wegas.git

Conflicts:
	wegas-app/src/main/webapp/wegas-app/js/plugin/wegas-scheduledatatable.js
	wegas-app/src/main/webapp/wegas-pmg/js/plugin/wegas-pmg-activitycolor.js