hdf5_der

[svn-r29817] Description:
    Sync w/trunk as of r29815.  Still working on a memory leak in the cache
image code/test (?), so not passing tests when memory sanity checking is enbled.

Tested on:
    MacOSX/64 10.11.4 (amazon) w/serial & parallel
    (h5commttest not required on this branch)