ENH: align fileOperations/masterUncollatedFileOperation findInstance()

- adds handling of negative start times for masterUncollatedFileOperation
  as well (#1112).

- handle failures *after* restoring non-parRun mode.
  This ensures exit(FatalError) will exit MPI properly as well.

STYLE: replace "polyMesh" with polyMesh::meshSubDir

STYLE: adjust IOobject read/write enumerated values

- provision for possible bitwise handling

applications/utilities/mesh/conversion/fluentMeshToFoam/fluentMeshToFoam.L

@@ -1698,7 +1698,7 @@ int main(int argc, char *argv[])
         fileName bczf
         (
             runTime.path()/runTime.constant()
-           /"polyMesh"/"boundaryAdjacentCellZones"
+           /polyMesh::meshSubDir/"boundaryAdjacentCellZones"
         );
 
         OFstream boundaryCellZonesFile(bczf);