added classify cmd option

added classify cmd option; so that the `classify` examples from [tutorial](http://factorie.cs.umass.edu/tutorials/UsersGuide01Introduction.scala.html) could be executed, e.g.:

```
$ bin/fac classify --read-text-dirs sportsdir politicsdir --write-classifier mymodel.factorie
```
Merge pull request #125 from neil-rubens/patch-1

added classify cmd option
added option to tokenize venues because this gets better results on rexa data
Fixed LDAUtils to return proportions instead of counts when inferring topics for papers. Author coreference has returned to its usual performance.
Merge pull request #126 from michaelwick/merge-change

added option to tokenize venues because this gets better results on rexa...