saveNetworkStructureXML now takes 8 arguments instead of 7.

The command "~/neuroConstruct/nC.sh -python GenerateNeuroML.py" fails with the error:
TypeError: saveNetworkStructureXML(): expected 8 args; got 7

Since 2013-10-30, saveNetworkStructureXML in neuroConstruct's NeuroMLFileManager.java takes an 8th argument: filesToInclude. This is an optional feature, so if we set it to a null value we get equivalent XML output to before.