hdf5_ep

[svn-r8907] Purpose:
To add collective chunk IO tests.

Description:
three tests are added.
1. Only one hyperslab for each process, and this hyperslab is fit in exactly one chunk.
2. non-contiguous hyperslabs in each process, these hyperslabs are fit in one chunk.
3. Single hyperslab for each process, smaller chunk is assigned. Number of chunks for
  every process is equal.

Solution:
the dataset size is set to be very small, will enlarge later.


Platforms tested:
AIX 5.1(copper)

Misc. update: