hdf5_ep

[svn-r22121] Purpose:
  update for HDFFV-7523 JPSS: h5dump fails to open an attribute when using the -a option to specify an attribute with a slash in the name

Description:
  Added capability for "-a" option to show attributes containing "/"
  by using an escape character. For example, for a dataset "/dset"
  containing attribute "speed(m/h)", use "h5dump -a "/dset/speed(\/h)"
  to show the content of the attribute. 
  Merged from HDF5 trunk r22052, r22063, r22108

Tested:
  jam (linux32-LE), koala (linux64-LE), ostrich (linuxppc64-BE), tejeda (mac32-LE),  Windows (32-LE cmake), Cmake (jam)