Fixed the duplicate slots view.
The script would not clear the screen upon recalculation also the list of duplicates would increase with every iteration because the variables weren't properly reset.
Patch by: Merio Ferraro, Lennard de Rijk
Reviewed by: to-be-reviewed
"""
Code used in a couple of places to work with the current thread's environment.
Current users include i18n and request prefix handling.
"""
try:
import threading
currentThread = threading.currentThread
except ImportError:
def currentThread():
return "no threading"