hdf5_der

[svn-r30227] Bring revisions #29743 - #29857 from trunk to page_buffering branch.
Tested on mayll, platypus, osx1010test, emu, moohan, kituo, kite, quail.
The test failure: testpar/test_page_buffer_access (testpar/t_file.c) related to
"entry_ptr->coll_access" still needs to be addressed.