[atriolo]

• Added methods to support digitization for kIRIS4a (3 petals) and kIRISFullCyl (1 petal = full cylinder) geometries.
• The digitization for the kIRIS4 (4 petals) geometry works as before.
• The kIRIS5 geometry (4 petals, but flat first layer) is not supported. At the moment, we do not foresee using this geometry for any study.
• Now the length of the petals and the number of pixel rows per petal used in the digitization are not hardcoded anymore, but are calculated based on the simulated geometry.
• Digitization and clusterization codes that were using the hardcoded number of rows per layer have been modified to get the number of rows as a function of the geometry.