Use the consolidate function for min or max series

When the function maxSeries or minSeries is called, the consolidate function
'min' or 'max' was added to the TimeSeries created in order to have a better graph.

Also, the aggregation function of the whisper serie is retrieved, so
the TimeSerie could be created with the good consolidate function
Patch for 'normalize' that crashed with empty set
Function that exacerbate the extrema of a graph