Updated in accordance with the nee pileup trees stucture.
Updated the instructions.
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
StiDetectorBuilder: Added method to remove a previously added Sti detector/volume
StiDetectorBuilder: Modified detector accessor to handle invalid detector requests in somewhat more graceful way
Uniform improvements in Sti objects output streamers
Remove unused variables
Added new data member to keep track of track energy losses in the node