hdf5_ep

[svn-r761] Changes since 19981013
----------------------

./src/H5.c
	Fixed a signed vs. unsigned comparison.

./src/H5D.c
	Setting a fill value of all zeros will cause the fill value to
	be written to the dataset instead of relying on the low-level
	file driver initializing unwritten areas with zero.

./src/H5D.c
./src/H5F.c
./src/H5Fprivate.h
./src/H5G.c
./src/H5Gpkg.h
./src/H5Gprivate.h
./src/H5O.c
./src/H5T.c
	More file mounting stuff.

./src/H5I.c
	Fixed a bug where trying to close an invalid object id caused
	a core dump.  For instance, H5Gclose(-1).

./MANIFEST
./test/Makefile.in
./test/mount.c		[NEW]
	Mounting tests.

./src/H5R.c
	Fixed a couple (herr_t)NULL casts.