Enable X-Forwarding in Vagrantfile
Merge pull request #1145 from cosmoharrigan/x-windows

Enable X-Forwarding in Vagrantfile
Fix test_dyn_feat_hc_breadth_first scores (-33 -> -26)

Commit e378d9c contains a change modifying the semantics of
ctruth_table_bscore so that the best possible score is 0 (the number
of errors impossible to avoid in the dataset are added to the
score). This test had not been changed due to being deactivated.