Gaudi parser cannot handle python tuples with exactly one element

Re-posting from GAUDI-1272, which seems not to have been picked up after a year and a half...

The following sequence of operations fails:

1. Declare a tool/alg with a vector property
2. Set the value in python as a list with only one element
3. Lock the tool. This causes initialisation to fail because the list is converted to a tuple, and the Gaudi parsers apparently cannot cope with the python syntax:

#include "GaudiKernel/Parsers.h"
std::vector<int> out;
Gaudi::Parsers::parse(out,"(0,1)").isSuccess() //this is true!
Gaudi::Parsers::parse(out,"(0,)").isSuccess() //this is false!

– example from ROOT prompt thanks to Will Buttinger. An Athena-based example is at /afs/cern.ch/work/k/khoo/public/OneElementListTest. Presumably the parsers should be taught to recognise the special case of "(something,)" which denotes a one-element tuple, so they don't attempt to split the string on ',' in this case.