Import Geant4 10.3.1 source tree

ReleaseNotes/ReleaseNotes4.10.3.html

@@ -63,7 +63,7 @@ User Documentation</A> for further information about using Geant4.
 
 Platforms:
 <UL>
-<LI>Linux, gcc-4.8.4.<BR>
+<LI>Linux, gcc-4.8.5.<BR>
     Tested on 64 bit architectures (Intel or AMD) with
     CERN CentOS Linux 7 (CC7) (based on CentOS Linux 7).</LI>
 <LI>MacOSX 10.12 Sierra with clang-3.8 (Apple LLVM/Clang-8.0.0)</LI>
@@ -144,6 +144,16 @@ re-compilation) and a re-compilation of user applications is required.
     and schema validation thorugh network is already activated against it.</LI>
 </UL>
 
+<P> </P>
+<B>Senditive Detectors</B>
+<P> </P>
+<UL>
+<LI>An explicit call to G4SDManager::AddNewDetector() <U>must now be added</U>
+    in order to register a sensitive-detector. The use of
+    G4VUserDetectorConstruction::SetSensitiveDetector() no longer does
+    this implicitly.</LI>
+</UL>
+
 <P> </P>
 <B>Electromagnetic and optical physics</B>
 <P> </P>