added year headings
Merge pull request #438 from jskda/master

encoding option for doctest files for test running
fixed tadm trainer gzip encoding broken by previous release, and made opening gzip unicode files a function instead of a class
fixed problems in data.py so data.doctest passes; the nltk protocol now supports absolute paths; the file protocol now understands zip files
python 2.7 pickle compatibility
the TODO is not needed anymore: load() supports loading zip files