added template generation to the demo; hackish solution so discarded duplicate templates will not remain in memory
Rule.__hash__() now computed from Rule.__repr__() (a bit easier)
added deterministic sort for template statistics (Counter.most_common() will not break ties consistently in different python versions)
version [2.6,2.7,3.2,3.3]  compatibility: uniform strings in Rule.__repr__(); explicitly numbered fields in '{}'.format()
added more stats to the trainers
added more info in print_template_statistics
added to demo.postagging