hdf5

[svn-r17720] bug fix:
h5repacktst creates some files that h5repack.sh reads, therefore, h5repacktst
must run before h5repack.sh runs. Added such a dependency.

Tested: Jam by hand (running "make h5repack.sh.chkexe_" and see that
h5repacktst is invoked first and until it finishes, h5repacktst does not run.)