hdf5_der

Fixed typos in H5MF_try_close(), and failure to handle the
file open followed immediately by file close case.

Also hooked up sanity checks directed at detecting modifications
to free space managers after they have been settled on file close.

Assertion failure in test/mf remains (disabled).

(cherry picked from commit 7ff7734b2eb988c00ebdbd7d396d4525f317c1e3)