ENYO-2446: Drag'n'drop in file manager with HTML5 "draggable" attribute

ENYO-2446: Drag'n'drop in file manager
* use of HTML5 "draggable" attribute
* folder node expansion on hold over
* "package.js" update

Checked on Windows 7 : Chrome, Chrome Canary
Note: 
* autoscroll currently only works on Chrome, Chrome Canary, Opera
* autoexpand currently only works on FF21, Chrome, Chrome Canary, Opera, Safari and IE10

Ready to be reviewed

Enyo-DCO-1.1-Signed-off-by: Vincent HERILIER <vincent.herilier@hp.com>