Fix DistributedMesh unique_ids from InfElemBuilder
Fix DistributedMesh unique_ids from InfElemBuilder

Before we were getting duplicate ids near boundary elements with
multiple boundary sides.

libMesh/libmesh,libMesh/libmesh,dschwen/libmesh,dschwen/libmesh,jwpeterson/libmesh,libMesh/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,libMesh/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,dschwen/libmesh,dschwen/libmesh,libMesh/libmesh,libMesh/libmesh,roystgnr/libmesh,roystgnr/libmesh,dschwen/libmesh,roystgnr/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,dschwen/libmesh,BalticPinguin/libmesh,libMesh/libmesh,roystgnr/libmesh,libMesh/libmesh,roystgnr/libmesh,dschwen/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,dschwen/libmesh,roystgnr/libmesh,jwpeterson/libmesh,roystgnr/libmesh