fix csv transient test in parallel 

Don't merge yet!

This fixes the csv_transient test in MPI parallel.... but I haven't resolved the threading issue yet.

The problem with MPI was that MooseVariable was checking `isSemiLocal()` for `reinitNodes()` which is wrong because that will be true even for nodes that are not owned by this processor but "border" this processor... leading to double counting in `SumNodalValuesAux`

refs #2899