Implemented a leave-one-out cross-validation method.
Extended predict method for gekm to include confidence intervals.
Added several methods for gekm objects: confint, logLik, loo, plot, sigma, summary, vcov, logLikFun, logLikGrad.
Corrected typos in the Rmd files.
Added the data sets 'consTPM' and 'consVSA' - thanks to Carla Henning for providing the data and granting permission for publication.