Tag GaussianMixtures v0.0.3

Changes
 - small improvements in README.md
 - fixed positive definite property of Variational Bayes covar matrix: sharpening of VGMM to GMM now works
 - compute lowerbound to the likelihood for Variational Bayes models
 - major speed up improvementent for VGMM training ~ 30x faster using BLAS and explicit loop programming
 - rudimentary support for multiple training files fort CGMM training