hdf5_ep

[svn-r11728] Purpose:
To support collective chunk IO, obtain the chunk addresses globally from one process.

Description:
Implement a call-back function to iterate B-tree to do the job.
Check in this code for major check-ins later.
Solution:

Platforms tested:
heping(Linux)
Should not be used by any library functions now, so won't affect library and tool tests.
No need to test on 3 platforms.


Misc. update: