Merge branch 'dev/20.8_merge' into 'multithreading'

update to tags from 20.8.X rel_3 on 2016.02.22

This MR contains all the tags that were in 20.8.X-VAL/rel_3 on 2016.02.22 that were not in dev/rel_3, except for the Externals, which will be handled in another MR.

Full list of tags is:

```
AthenaCommon-03-03-21
AthExHive-00-05-11
CaloG4Sim-00-02-52
CaloHiveEx-02-05-11
CombinedScintillator-00-04-00
DeadMaterial-00-02-00
ForwardRegionMgField-01-01-00
G4AtlasAlg-00-10-06
G4AtlasApps-00-12-00-15
G4AtlasControl-00-07-02
G4AtlasInterfaces-00-00-40
G4AtlasServices-00-04-13
G4AtlasTests-01-02-04
G4AtlasTools-00-04-00
G4CosmicFilter-00-01-07
G4HitFilter-00-00-10
G4HiveEx-00-03-20
G4ProfilingTools-00-00-05
G4UserActions-00-01-24
Geo2G4-00-09-00
GeoMaterial2G4-00-00-01
GeoSpecialShapes-00-03-00
ISF_Algorithms-00-05-00
ISF_Geant4Config-00-01-25
ISF_Geant4Event-00-00-05
ISF_Geant4Tools-00-12-08
ISF_Geant4UserActions-00-05-00
ISF_HepMC_Tools-02-00-02
ISF_Interfaces-00-05-01-05
ISF_Services-01-01-02
LarCrate-00-02-00
LArG4Barrel-00-03-03
LArG4Code-00-11-04
LArG4EC-00-03-04
LArG4FastSimSvc-01-00-12
LArG4FastSimulation-05-01-01
LArG4FCAL-00-03-00
LArG4GenShowerLib-01-01-03
LArG4H6SD-00-05-00
LArG4H8SD-00-03-00
LArG4HEC-00-03-00
LArG4MiniFCAL-00-02-02
LArG4SD-01-04-02
LArGeoEndcap-00-00-90-02
MagFieldInterfaces-00-01-15-02
MagFieldServices-00-01-33-02
MCTruthBase-00-02-10-01
MuonSimValUtils-00-00-07
MuonWall-00-04-00
PhantomCalorimeter-00-04-00
Quirks-00-01-02
RHadrons-00-01-05
SCT_DigitizationRTT-01-00-00
SimHelpers-00-02-00
TrigJetHypo-03-00-64
TrkG4UserActions-04-00-01
TRT_RawDataByteStreamCnv-00-03-20
TRT_TR_Process-00-02-01
```

See merge request !231