CompositePulses are now iterable too

with @blakejohnson

QGL/PatternUtils.py

@@ -278,7 +278,7 @@ def convert_lengths_to_samples(instructions, samplingRate, quantization=1):
 # from Stack Overflow: http://stackoverflow.com/questions/2158395/flatten-an-irregular-list-of-lists-in-python/2158532#2158532
 def flatten(l):
     for el in l:
-        if isinstance(el, collections.Iterable) and not isinstance(el, (str, Pulse)) :
+        if isinstance(el, collections.Iterable) and not isinstance(el, (str, Pulse, CompositePulse)) :
             for sub in flatten(el):
                 yield sub
         else: