StiPxlDetectorBuilder: Don't proceed if the DB information is not available
StiPxlDetectorBuilder: Removed unused include
StiPxlDetectorBuilder: Got rid of redundant char array holding the volume's name. It also helps to have Sti volume names as close to the original TGeo ones as possible
StiPxlDetectorBuilder: No need to explicitly define individual volume instances in the list. The averaging procedure can create separate Sti volumes for all volume occurancies in TGeo
Added some more inactive material close to the silicon layers