Development of the AFP TOF signal digitization + some fixes

Development of the AFP TOF signal digitization. Added functionalities to the AFP_PileUpTool class which transform information about optical photons reaching the PMTs into signal and later into digitized ADC and TDC. The outcome of the simulation+digitization has been tuned to describe the data (the silicon tracker part). The time (TDC) signal from TOF has been calibrated with the simulated exclusive p+p->p+WW+p events such that the time response in each PMT channel is the same (on average; integrated over all proton hit positions).

Apart from development did also some code cleaning, corrected indentations and introduced two fixes:

• fixed ATLASRECTS-4833,
• fixed ATLASRECTS-6753 (this is in AFP_Geometry; picked commit bce74715 which has been already applied to master).