changed tree node property to a method, and added a set_node method (following the model of prob/set_prob etc in probability.py)
fix the node setter in ImmutableTree
Merge branch 'master' of https://github.com/stevenbird/nltk
Merge branch 'master' of https://github.com/nltk/nltk
Tree.node() and Tree.set_node() changed to Tree.label() and Tree.set_label(); Tree.node() raises notImplementedError
removed emacs files inadvertently included with commit
use label() method in place of node attribute
Merge pull request #502 from stevenbird/master

change tree node property to a method
Fixed bug in code to find right peak; resolves https://github.com/nltk/nltk/issues/408