Changes in version 2.99.4:
    + Improved label- and axis handling for panels with continuous covariates
    + Formally deprecated heatmap_2 and heatmap_plus
    + Refactored to switch to devtools tool chain

Changes in version 2.23.1
    + Resolved issue with inconsistent plotting on the same device

Changes in version 2.15.2
    + New color scheme for clusters to make neighboring clusters distinct

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)