normalblockr v0.2.1 - first CRAN release

normalblockr 0.2.1

First CRAN submission

• S3 methods print(), summary(), plot(), logLik() and BIC() for fitted models (any NormalBlockVarBase subclass), and print()/summary()/logLik()/BIC() for collections of models; accessing $loglik on a collection now raises an informative error instead of silently returning NULL.
• Shortened/title-cased man page titles, added missing @examples, cross-referenced $plot_network()/$latent_network() in each other's documentation, and replaced a few inefficient matrix operations (solve() on symmetric positive-definite matrices, M %*% t(C)) with chol2inv(chol())/tcrossprod().