tuned on urdu baselines (hiero) devtest, test on mt09

hdt: single pass (no pruning of -LM forest).  these weights were used for the
final +LM rescoring in all cases. (tune BLEU 22.2)

2pass-hdt: 1st pass weights same as final weights (bad) (tune BLEU ???)

2pass-hdt0: 1st pass weights tuned without any lm (same final weights as hdt). (tune BLEU 14.7)

2pass-hdt1: 1st pass weights tuned with unigram lm (same final). (tune BLEU 16.2)

data files / graphs: 2nd column is BLEU

2pass-hdt - first column is beam alpha scaled per source word.

times.2pass-hdt - first column is +LM rescoring time

space.2pass-hdt - first column is portion of -LM forest edges kept

It would be nice to graph these with the same scale, or preferably as 3 lines in
the same graph.