SequenceSemantics: cannot compare with plain list

The comparison operator of the _ListHelper is too restrictive. One should be able to compare a list property to a plain list:

from GaudiConfig2.Configurables import PropertyAlg
alg = PropertyAlg()
alg.StringArray = ['foo']
alg.StringArray == ['foo']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/scratch/fwinkl/Gaudi/src/GaudiConfiguration/python/GaudiConfig2/semantics.py", line 325, in __eq__
    return self.data == other.data
AttributeError: 'list' object has no attribute 'data'