add single options to create_bonds command

src/create_bonds.h

@@ -30,9 +30,15 @@ class CreateBonds : protected Pointers {
   void command(int, char **);
 
  private:
-  inline int sbmask(int j) const {
-    return j >> SBBITS & 3;
-  }
+  int igroup,group1bit,group2bit;
+  int btype,atype,dtype;
+  tagint batom1,batom2,aatom1,aatom2,aatom3,datom1,datom2,datom3,datom4;
+  double rmin,rmax;
+
+  void many();
+  void single_bond();
+  void single_angle();
+  void single_dihedral();
 };
 
 }