Revert "Make Exodus reader respect the numbering in node_num_map."

This reverts commit c4a7cd1a714b84bb94a8267e300bd97382b53f61.
Revert "Make Exodus reader respect the numbering in elem_num_map."

This reverts commit e669b64e17f5c2dfad9034dcf4669a3e0d0f2386.