added option to kill parents with join workouts

rowers/dataprep.py

@@ -408,7 +408,7 @@ def filter_df(datadf, fieldname, value, largerthan=True):
 def join_workouts(r,ids,title='Joined Workout',
                   parent=None,
                   setprivate=False,
-                  forceunit='lbs'):
+                  forceunit='lbs',killparents=False):
 
     message = None
 
@@ -477,6 +477,10 @@ def join_workouts(r,ids,title='Joined Workout',
                                         dosmooth=False,
                                         consistencychecks=False)
 
+    if killparents:
+        for w in ws:
+            w.delete()
+
     return (id, message)