- H5PartSetNumPoints() renamed to H5PartSetNumItems()
- H5PartGetNumPoints() renamed to H5PartGetNumItems()
- Dataset names longer then 64 bytes are handled as error.
- Same for step/iteration names.
* core API
- we use the term 'iteration' instead of 'step'
- we use the term 'item' instead of 'point'
- re-factor function and variable names
- in printing messages/debug output fixed
- do not flush (sync to disk) after writing a dataset by default,
  can be controlled by a property