Example was modified to use references to different objects.
Missing calls to release dataset handles and to free memory buffers were
added.
Tested on baldric.
h5_select.c was modified to use fill values, and h5_group.c was modified
to show how H5Giterate can be used to get information about the objects in
a group.
Necessary changes were done to the Makefile.in.
Tested on Solaris 2.6 (baldric)