Add action event handler function to do refresh of the pending pull and pending approval requests.  This will call the data model to obtain the backing data for the pending pull and pending approval lists of requests.  This function will block the UI as they are not run on a worker thread.
Add buttons to do refresh all and refresh pending within a vertical box to the busy panel.  Show in the case of query failure.  This will give the user the option to try to refresh the data to a useable state or go do something else.  This should avoid the loop of refresh - fail - refresh - fail ...
Add removeLeafNonValueItems call to DataModelBusyListener to clear out empty carts after a successful commit.
Add code to refreshPending function to remove the busyPanel overlay in the event of success or failure.
Add stub for refreshAll function and set it as the action for the button in FXML.
Implement refresh pending approval, refresh pending pull, and refresh completed requests as three separate utility functions.
Implement the refresh all button action.
Modify the refresh pending button action to use the utility functions.
Begin implementation of entry remove/delete functionality.
Update display methods and style for items marked for deletion.
Remove setOnDragDone event handler from Tree Cell.  It was not doing any useful work anwyay.
Make minor comment updates and style updates.
Update Request controller to handle cancel edits of items marked for deletion.
Updated the DataModel to force backups to use the marked for deletion flag.
Make it so that the data model will only include null for the new version in the backup list.  This will mean that all subsequent cart changes to an item marked for deletion will not be commited to the database.
Add functionality to requests worker thread of the data model to allow it to remove entries.
Add second mod worker thread class that takes a map<request,request> instead of two lists of requests.  This should allow an easy check for stale data.
Update req tree controller and data model to handle remove request objects.
Still need to update the listener in the request view controller to remove the proper tree items after the data model is done.