Basic support for WADE analysis

Partial support for running WADE (http://www.umiacs.umd.edu/~hal/damt/)
analysis from ems. You still need to create the input-reference alignments
somehow - for example by running training with the test set concatenated
to the training set.

To use WADE, (i) add 'wade = /path/to/wade.py' to the EVALUATION section and
(ii) add 'alignment = /path/to/alignments' to the approriate stanza
for each test set.