* improved uploading of files
- new core/UploadDirective to allow dropping files to any html element
- enhanced file dropping for DataTable rows (disabled by default)
- enhanced file dropping for DocumentList rows (disabled by default)
- upload drop area now handles file uploads for child elements (i.e.
rows in the document list)
* fix unit tests
* unit tests and code cleanup
* #1732, fix upload of folders
* Fix typo `fallbackThubnail` -> `fallbackThumbnail`
* Fix typo `showUdoNotificationBar` -> `showNotificationBar`
Update upload mis-spelled properties to 'showNotificationBar' since
showUndoNotificationBar is already a method on the drag area component
Refs #1559
* Fix test cases
