fixed doctype regex to handle doctype tag w/o square brackets
nltk.util doctests are fixed for Python 3.x
fix LazyCorpusReader._unload once again
Fix corpus.doctest (I have no idea why it starts failing again)
Fixes unicode issues in downloader by changing the XML attrib values to unicode strings.
corpus.doctest is fixed for Python 3.3
make Package and Collection sortable, so that the downloader works in Python 3
Some stability issues in resolution.doctest are fixed by making AbstractVariableExpression orderable and BindingDict.__str__ stable.
Merge pull request #344 from alexrudnick/master

Two fixes for nltk.downloader
almost fixed it; want to make the decisiontrees demo work right with the binary attribute set to true
Fix the decision stumps so that they work on Python 3, and are robust to not seeing a positive or negative examples.
Merge pull request #336 from cadaeib/fix_xmlcorpusreader

fixed doctype regex to handle doctype tag w/o square brackets
Merge remote-tracking branch 'upstream/master'
Merge pull request #346 from alexrudnick/master

Fix for decision trees with binary=True
applied patch from Tomonori Nagano to fix pos tag issue, resolves issue 347
fix indentation error; still an issue with line 323
re-apply patch from Nagano
Escape reserved chars in Tree.pprint_latex_qtree()
Merge pull request #348 from stesh/master

Escape reserved LaTeX characters in nltk.tree.Tree.pprint_latex_qtree()
Python 3.3 compatibility for nltk.internals.ElementWrapper. Thanks @achimnol. Fixes #350.