hdf5_der

[svn-r20237] Interrim checking of AIO VFD mods.

Finished a reasonably complete set of tests for AIO on sec2, and extended these tests
to the core, stdio, family and multi file drivers.  Note that the multi file
driver has some test code specific to it.  Also added tests for the new fsync
VFD call.

Code has been tested successfully on Phoenix (Debian AMD_64) serial and parallel,
Jam (32 bit linux) heiwa (big endian linux), and freedom (bsd) (all serial only).
Note that the test on freedom requires the manual addition of

/* JRM */
#if 0
#define __BSD_VISIBLE 1
#include <sys/fcntl.h>
#endif
/* JRM */

near the top of src/H5FDdirect.c.  For now, just replace the 0 with 1 in the #if
to compile and test on BSD.  This is a configuration issue that I'll address
with the rest of the outstanding configuration issues when appropriate.

Test are known not to pass reliably on Linew and expected not to pass on MacOS.

Ran into considerable wierdness on checkin, with svn complaining about missing
files.  Finally had to checkout fresh version of code, port changes to it, and 
re-tests.  Odd, as the log indicates no activity on this branch since my last
checkin.