Added error checks to user actions
Added  user level checks for adding, moving, and renaming directories
adding and moving directories now work with both absolute and relative paths.
Fixed bug where were directory was allowed to move into itself.
Merge remote-tracking branch 'jesse/master'
Merge remote-tracking branch 'eric/master'
added dbfs alerts when modifying to the dbfs fails
Merge remote-tracking branch 'eric/master'
Edited JSON function  in model.