Structured grids
Some changes for structured grids IO
- HDF5_handler depends only on spatial grid descriptors
- Add supporto to polymorphic grid descriptors
- Generalization and refactoring of handlers.
- Fix HID_T and HSIZE_T types inheritance
- Starting XH5For redesign.
- Implemented a temporal toy factory to make easy the structured layer implementation.
- first steps implementing unstructured spatial grid descriptor.
- Make spatial_grid_descriptor variables private.
- Add XDMF_GEOMETRY_TYPE_X_Y_Z support
- Add I/O procedures for XDMF_GEOMETRY_TYPE_ORIGIN_DXDYDZ geometries.
- Set TopologySizePerGrid from XDMF_Handler.
- Add initialization procedures to concrete grid descriptor
- Add GridType to initialization procedures and allgather/broadcast communications.
- Remove optional attribute of the GridID dummy argument in XDMF handlers
- Move WriteAttribute procedures from concrete HDF5 handlers to abstract handler strategy layer.
- Add some structured tests and exampeles