Add DenseMatrix constructor taking a std::initializer_list
Add DenseMatrix constructor taking a std::initializer_list

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