Added option in delete to clear the cache
Fixed bug in DataSet.latest so that orphaned data is returned if it exists
Added option to delete orphaned data in delete command
Refactored run so that models and views are only collected if they are going to be run
Set code to set ids to empty list if no ids are provided
Set confirmation input to be set to lowercase
Moved setting of results list in DataSet.history to after break statement
Fixed bug in DataSet.history and refactored this function