Package GMMs

Hello, 

This is a package that I have been working on for a very long time now, GMMs or Gaussian Mixture Models.  It focuses on fairly big models (~2000 Gaussians of ~60 dimensions are not uncommon, where training data might encompass ~ 10^9 or more data points).  It has support for training the models on a computing cluster (using ClusterManagers) where data is passed to the training algorithm by streaming from disc. 

This week I accomplished some more inner-loop efficiency improvement and I further incorporated the package BigData that seemed not to be viable to live on its own, unfortunately.  I even managed to put together a travis automatic test.  (I tend to first write a package before I package it so that I can't call Pkg.generate()).  I finally changed the license to MIT. 

Cheers, 

---david