hdf5_der

[svn-r28952] Check in of:

1) Code to maintain and display metadata cache image specific
   statistics.

2) Code to avoid modification of the file driver info superblock 
   extension message during superblock serialization, and to 
   repair (all but one of the) bugs exposed by this change.

   With this checkin, the superblock and superblock extension
   metadata cache flush rings are now distinct.

3) Fix to metadata cache flush sanity checking code.  This 
   fix was originally written for Mohamad in early September 2015,
   but somehow didn't make it into the cache image branch.  This 
   oversight is repaired here.

4) Cleanup of debugging and obsolete code.

Note that this checkin does not repair a property list management
bug in objcopy that appears to have been exposed by item 2) above.
This bug appears when objcopy is run with either the split or multi
file drivers.  The easiest way to reproduce it is to run a check-vfd
build, and then grep for "Error detected".  Sample error output 
follows:

**********************************************************************
...
============================
Testing split objcopy
Finished testing objcopy
============================
split objcopy  Test Log
============================

Testing without shared src messages:
Testing without shared dst messages:
Testing with oldest file format for source file:
Testing with oldest file format for destination file:
Testing H5Ocopy(): simple dataset                                      PASSED
Testing H5Ocopy(): simple dataset within the same file                 PASSED

...

Testing H5Ocopy(): expand object reference                             PASSED
Testing H5Ocopy(): preserve NULL messages                              PASSED
Testing H5Ocopy(): preserve NULL messages                              PASSED
Testing H5Ocopy(): copying objects while opened                        PASSED
HDF5-DIAG: Error detected in HDF5 (1.9.233) thread 0:
  #000: H5P.c line 1519 in H5Pclose(): can't close
    major: Property lists
    minor: Unable to free object
  #001: H5I.c line 1287 in H5I_dec_app_ref(): can't decrement ID ref count
    major: Object atom
    minor: Unable to decrement reference count
  #002: H5I.c line 1217 in H5I_dec_ref(): can't locate ID
    major: Object atom
    minor: Unable to find atom information (already closed?)
All object copying tests passed.
153.92user 3.92system 2:39.19elapsed 99%CPU (0avgtext+0avgdata 44188maxresident)k
0inputs+311264outputs (0major+100822minor)pagefaults 0swaps

Finished testing objcopy
============================
...

**********************************************************************

Note that this failure does not flag a test failure.  The bug
was detected in a manual scan of a check-vfd build and regression
test.

Tested on Jam      (serial/debug)
          Mercury  (serial/debug, parallel/debug, serial/check-vfd/debug)

All tests passed except as noted above.