hdf5_ep

[svn-r21151] Description:
  Merged from HDF5 trunk r21105

  Fixed two bugs:    
    - h5repack: h5repack failed to copy dataset if the layout is changed from c
      hunked with unlimited dims to contiguous. (PC -- 2011/07/15)
    - h5diff: "--delta" option considers two NaN of the same type are different
      , which is wrong based on http://www.hdfgroup.org/HDF5/doc/RM/Tools.html#Tools-Diff.  (PC -- 2011/07/15)

Tested:
  jam (linux32-LE), koala (linux64-LE), heiwa (linuxppc64-BE), tejeda (mac32-LE), linew (solaris-BE)