hdf5_ep

[svn-r8391] Purpose:
Checkpoint checkin of FP bug fixes.  FP is still quite
buggy, but I must go deal with other matters.


Description:

Fixed two major bugs:

1) H5FPserver.c was clobbering meta data in its care.

2) H5FPserver.c was allocating the same space multiple
   times, causing both data and meta data corruption.

Also made minor fixes, added debugging code, and familiarized
myself with the FP code.

All development work with FP enabled was done on Eirene.
On this platform, FP now passes its test reliably with
up to 9 processes.  At 10 processes it seg faults every
time.  I haven't looked into this issue.

There are also several known locking bugs which have to
be fixed.  However, they are of sufficiently low probability
that I didn't bother with them on this pass.

FP has not been tested with deletions -- this should be
done.

Also, need to test FP chunked I/O.


Solution:

1) Modified cache in H5FPserver.c to merge changes correctly.
   Found and fixed a bug in H5TB.c in passing.

2) Multiple space allocation was caused by a race condition
   with set eoa requests.

   Most of these eoa requests appeared to be superfluous, so
   I deleted them.

   Those issued during the superblock read seemed necessary,
   so I inserted a barrier at the end of the superblock read,
   to prevent races with allocations.

Platforms tested:
h5committested