GNodeArray now derives from GContainer class.

The node array class now derives from the container base class. All typical container methods, such as at(), size(), isempty(), append(), insert(), remove(), reserve() and extend() are now implemented. Unit tests have been added to check the functionnality.

The Python interface now implements the __len__ method on the GContainer class level. This allows to determine container sizes using the len() function. The __len__ method is now obsolete in the derived classes and thus has been removed.
Review GTools and GCsv class.

Some arguments that were not already passed as const references are now declared as const references. Inline methods were added to GCvs.
Put methods inline.