fix problem when writing multiple models.

This is a regression from the io-profiles branch.

modules/io/pymod/__init__.py

@@ -204,7 +204,7 @@ def SavePDB(models, filename, dialect=None,  pqr=False, profile='DEFAULT'):
   writer=PDBWriter(filename, profile)
   writer.SetIsPQR(pqr)
   if len(models)>1:
-    writer.SetMultiModel(True)
+    writer.write_multi_model=True
   for model in models:
     writer.Write(model)
 

modules/io/pymod/export_pdb_io.cc

@@ -72,6 +72,10 @@ void export_pdb_io()
     .def("Write", write_a)
     .def("SetIsPQR", &PDBWriter::SetIsPQR)
     .def("IsPQR", &PDBWriter::IsPQR)
+    .def("SetWriteMultiModel", &PDBWriter::SetWriteMultiModel)
+    .def("GetWriteMultiModel", &PDBWriter::GetWriteMultiModel)
+    .add_property("write_multi_model", &PDBWriter::GetWriteMultiModel, 
+                  &PDBWriter::SetWriteMultiModel)
     .def("Write", write_b)    
   ;
 }