1.0
    * Added support for L2 penalization(alpha=0);
    * hqreg: changed argument "loss" to "method" and an option "squared" to "ls".

1.1
    * loss.hqreg.R: corrected a mistake in function "qloss".

1.2
    * cv.hqreg: added two new arguments, "fold.id" for predefined cross-validation 
      folds, and "type.measure" for inclusion of general error measures "mse" and 
      "mae".
    * loss.hqreg: modified definition depending on "type.measure".

1.3
    * cv.hqreg: enabled parallel computing for cross-validation with a new argument "ncores"
    * hqreg: set the default value of "gamma" for Huber loss to be IQR(y)/10
    * plot.hqreg, plot.cv.hqreg: changed argument "log.x" to "log.l"
    * removed computational redundancy and reduced memory allocation in source code
    * corrected typos in documentation

1.4
    * new function "hqreg_raw" for fitting models on raw data without preprocessing
    * hqreg_raw contains a boolean argument "intercept" which can be set to FALSE to allow a "no-intercept" fit
    * hqreg: no longer support preprocess = "none" since the package now has a specific function hqreg_raw for that situation
    * modified plot, predict function accordingly for the situation without an intercept
    * cv.hqreg: added a new argument FUN that take values from either "hqreg" or "hqreg_raw" to include cross validation
      functionality for hqreg_raw
    * robustified the optimization algorithm for extreme cases in quantile regression when tau is close to 0 or 1
