Changes in version 2.0.0
    + Add both row- and column annotation via annHeatmap2
    + New function regHeatmap as replacement for heatmap_2
    + New function annHeatmap as replacement for heatmap_plus
    + Support for heatmap_2, heatmap_plus will be dropped (deprecation warning)    
    + Mutiple continous covariates for annotation possible (picketPlot)
    + Simple legend also for annotated heatmaps (annHeatmap2)
    + More detailed interface for specifiying graphical parameters (annHeatmap2)
    + Green-to-red palette as new default (annHeatmap2)

