Version 0.7.4
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Minor bug fixes

Version 0.7.2 and 0.7.3
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Fixed some bugs introduced by changing the direction of plotting the y axis


Version 0.7.1
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* Added option to modify labels of the color scale legend (legend_breaks and
legend_labels)
* Changed the direction of plotting to start from the top instead of bottom on 
y axis.


Version 0.7
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* Added opportunity to show also the corresponding numeric values in the cells 
(see display_numbers parameter).
* Added opportunity to show unused factor levels for column annotations in the 
legend (drop_levels parameter). 
* Changed the order how the rows are drawn when rows are not clustered. Before 
it started from the bottom, now from the top.
* Changed legend positioning according to the presence of column names
* The function now returns invisibly all the clusterings that it performed.