Sgroup (#3390)

* Changes to use SubstanceGroups in Java

* Forgot to add SWIG file

* Java test for SubstanceGroup wrappers

* Added RDKit boilerplate

Code/JavaWrappers/csharp_wrapper/GraphMolCSharp.i

@@ -254,6 +254,7 @@ typedef unsigned long long int	uintmax_t;
 %include "../SubstructLibrary.i"
 %include "../ScaffoldNetwork.i"
 %include "../TautomerQuery.i"
+%include "../SubstanceGroup.i"
 %include "../MolHash.i"
 %include "../Streams.i"