Properly identify multiple hits of primary particle in TSolSimDecoder

Also, in TSolGEMData, it is sufficient to record fSource only once
instead of for every hit since all the hits of these GEMData are from
the same file.
Add missing include to make TSolSimDecoder::Print work
Export fRealSector truth information as global variable from decoder
Don't generate streamers for Planes, SolSpec and Digitization, do for Hits

Also fix some includes and whitespace.
Detector errors when initializing planes in TSolGEMChamber::ReadDatabase
Inline TSolGEMPlane::PlaneToStrip
Add sector mapping info to TSolSimEvent
Silence nuisance warning about missing truth information