Don't use DofObject copy constructor
Don't use DofObject copy constructor

If we take references instead then we can still run these tests even
with --disable-deprecated

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