Merged requested to merge mveghel-fastcorrections-dev into master
The majority of the time of the calo reco is now spent on shower overlap and correction calculations.
This MR introduces very fast approximations of exp, log, sqrt for corrections speedup from
Will increase speed of overlap/correction algorithms with 20-30%.
In addition, all these calculations should be done with
doubles as is now, as the precision needed is smaller than floating-point precision.
Note: in the CondDB the parameters for these corrections are stored as
doubles, but will be converted during initialization in the correction algos now.