OpenFOAM reader needs updating

[biagas]

Is your feature request related to a problem?

The vtk files in the OpenFOAM reader are based off VTK's, but are much older and VTK has made a number of improvements.

We should investigate if it is feasible to subclass their readers at this point in time.

Part of the reason for the current state of things was the need to make the Point/Face/CellZones names available to the avt portion of the reader for filling in DatabaseMetaData information. They are used to create new meshes (boundary meshes, I believe).

Logic was added to the 'Private' class function MakeMetaDataAtTimeStep of the vtk reader to prevent needing to reread the entire file again.
Logic was also added to GetFieldNames (also in the 'Private' classs) to save LagrangianArrayClassName as they were encountered.
I think the fact that these are part of the 'private' class within the reader made subclassing unworkable.

Describe the solution you'd like.

It would be nice to utilize the VTK reader by subclassing, in order to stay up-to-date, or to do away with use of VTK for this reader at all and implement our own.