take advantage of closure option for mbpart
When -c option is used for mbpart, the partition sets will contain, besides the primary entities, all lower dimensional entities in the "closure" local domain. This should be used in a intelligent way during hdf5 read.
Right now, when we read in parallel, the local partition contains just the primary entities, of the highest dimensional order. All lower dimensional entities are instanced in a local partition only if their vertices are in the partition. This verification is expensive though, because all tasks will have to read all lower dimensional entities.
Modifications should be done to hdf5 parallel reader. If the partition set will contain all "closure" entities, each task will do just a partial read of the lowest dim entities, it will cherry pick from the file. (in the same way only a few vertices are instanced on each task, only the vertices that are adjacent to primary entities).
this should scale much better, if there are a lot of lower dim entities (for example, for a file in which all faces and edges are created before saving them )
This option should be triggered with a read option, and the user should know in advance if the "closure" option was used for a partitioned file.