New calibration of F11 plastic

We decided to have both a low gain and a high gain 
for F11 plastic dividing the signal from the TFA 
with a "T" and using in one branch a 20db attenuator (reduction by 10)
and sending to two different DACQ channels.
The gain of the TFA was also reduced to x2

V1A7C3: F11_PL_R (Low gain: ~60MeV)
V1A7C4: F11_PL_L
V1A7C5: F11_PL_R_HG (High gain: ~600MeV)
V1A7C5: F11_PL_L_HG