new for version 1.19.1
======================
* Addresed an error in one of the internal functions fitting the null model distribution generated by the new way NAs are treated in R3.5.0+ lm() function

new for version 1.9.5
=====================
* metaVIPER analysis was implemented in the viper function. It can be invoked by simply passing a list of regulons objects to the regulon parameter in the viper function.

* To improve stability of p-value estimations with sample permutations, a normal distribution for the ES is assumed when less than 500 permutations are provided for the NULL model.

new for version 1.5.5
=====================
Example code was modified to reduce computation time

new for version 1.5.4
=====================
Added the argument processAll to msviperCombinatorial that allow the evaluation of synergy between pairs showing enrichment not significantly higher than the singe regulons

new for version 1.5.3
=====================
New implementation of the aREA algorithm allowing for missing values and weighting the contribution
of each datapoint in the expression matrix and 

new for version 1.5.2
=====================
New function aracne2regulon4cnv to parse ARACNe results generated by using different expression files for regulators and targets

new for version 1.5.1
=====================
Bug fixed in aracne2regulon function

new for version 1.3.2
=====================
Added function msviperClass ro generate instances of the msviper class

new for version 1.3.1
=====================
Use of multiple cores based on the parallel package

new for version 1.1.0
=====================
A bug in aracne2regulon function related to collapsing the regulons at the gene level was fixed

A bug in the aecdf function was fixed

Implemented a new pleiotropy algorithm

aREA function was rewritten with improved performance

Computation of empirical p-values was performed assuming a symmetric distribution of the ES around 0 for the NULL model, increasing in this way the power of the test by a factor of 2

A function to compute the similarity between VIPER signatures (viperSimilarity) was added to the package 

new for version 0.99.1
======================
Bug fixed in shadow() function that was crashing when one regulon was completely contained into another regulon.

