Module which implements a newick string parser as a finite state
machine which enables it to parse the full Newick specification.
Taken largely from the Ensembl Compara file with the same name
(Bio::EnsEMBL::Compara::Graph::NewickParser), this module adapts the
parser to work with BioPerls event handler-based parsing scheme.
This module is used by nhx.pm and newick.pm, and is NOT called
directly. Instead, both of those parsing modules extend this module in
order to gain access to the main parsing method.