[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)

tools/testfiles/tpbitsLengthPositive.ddl

@@ -10,6 +10,9 @@ usage: h5dump [OPTIONS] files
      -e, --escape         Escape non printing characters
      -V, --version        Print version number and exit
      -a P, --attribute=P  Print the specified attribute
+                          If an attribute name contains a slash (/), escape the
+                          slash with a preceding backslash (\).
+                          (See example section below.)
      -d P, --dataset=P    Print the specified dataset
      -y, --noindex        Do not print array indices with the data
      -p, --properties     Print dataset filters, storage layout and fill value
@@ -81,6 +84,10 @@ usage: h5dump [OPTIONS] files
 
       h5dump -a /bar_none/foo quux.h5
 
+     Attribute "high/low" of the group /bar_none in the file quux.h5
+
+      h5dump -a "/bar_none/high\/low" quux.h5
+
   2) Selecting a subset from dataset /foo in file quux.h5
 
       h5dump -d /foo -s "0,1" -S "1,1" -c "2,3" -k "2,2" quux.h5