trial3 is about to be made the main file
So far, the roles of the files have been as follows:
trial1- ordered attribute learning (no discovery)
trial4- ordered attribute+class (general concept) learning (no
discovery)
trial2- order discovery for attribute learning
trial3- order discovery for general concept learning

Now trial3 has a number of new options:
1. params.discoverStages allows turning the discovery part on and off.
2. params.addClasses allows adding classes to the list of variables to
be predicted.
With these, trial3 can do everything other files can. Hence being made
the master branch.

TODO: come up with a way to differentiate between the mat files trial3
creates with different parameter settings.