pedestal subtraction

[hashkar]

For now the pedetal sutraction is only applied to charge integration. To implement it the code is called with the "-n" option.
It will substract the mean of the first 20 ns of the WF from all events.
Check if this subtraction should be made for all events.
Also chekc if it should be added other modules.

[hashkar]

Also in the camera monitoring class we can have an average of all the pedestals in the first 20 ns for the entire camera