Merge pull request #305 from xylar/omega/fix-max-cells-on-edge-dim-read-order

Fix order of `MaxCellsOnEdge`/`TWO` dimension read

We want to try the new name first, then the old one.  As it stands, we get an error message like:
```
[error] [IO.cpp:343] PIO error while reading dimension TWO
```
even if `MaxCellsOnEdge` is then successfully read.  It isn't great that we're getting an error message at all but at least with this fix the error will only be logged if the old dimension name is being used.

Author: xylar

components/omega/src/base/Decomp.cpp

@@ -195,10 +195,10 @@ void readMesh(const int MeshFileID, // file ID for open mesh file
    DimName    = "MaxCellsOnEdge";
    DimNameOld = "TWO";
    I4 MaxCellsOnEdgeID;
-   Err = IO::getDimFromFile(MeshFileID, DimNameOld, MaxCellsOnEdgeID,
+   Err = IO::getDimFromFile(MeshFileID, DimName, MaxCellsOnEdgeID,
                             MaxCellsOnEdge);
    if (Err.isFail()) { // dim not found, try again with older MPAS name
-      Err = IO::getDimFromFile(MeshFileID, DimName, MaxCellsOnEdgeID,
+      Err = IO::getDimFromFile(MeshFileID, DimNameOld, MaxCellsOnEdgeID,
                                MaxCellsOnEdge);
       CHECK_ERROR_ABORT(Err, "Decomp: error reading MaxCellsOnEdge");
       if (MaxCellsOnEdge <= 0)