Alignment parameters obtained starting from the alignment parameters of the
colums (from test beam), by means of ground muons. 

STEP1
-----
Alignment parameters are first corrected for the AVERAGE shift (NB only
TRASLATIONS) of the PLANE (evaluated from residual distributions, obtained by 
using alignment parameters of the colums). 

STEP2
-----
Muon tracks crossing two different colums were selected, and parameters were
corrected for the relative misalignment of the colums. 
