[svn-r19401] Purpose:

Fix for Bug1975 h5diff - support recursive comparison on group when specified as an object

Description:
 Merged from hdf5 trunk (r19400).
 Compare member objects and groups recursively when two files or groups are specified to be compared. Support parallel diff and handling symbolic links accordingly.

Tested:
 jam, amani

tools/h5diff/testfiles/h5diff_502.txt

@@ -0,0 +1,36 @@
+
+group1   group2
+---------------------------------------
+           x                   
+    x           /              
+    x      x    /dset1         
+    x      x    /dset2         
+    x      x    /dset3         
+    x           /elink_grp1    
+    x           /elink_grp2    
+    x           /elink_grp3    
+    x           /grp1          
+    x           /grp1/dset1    
+    x           /grp1/grp2     
+    x           /grp1/grp2/dset1
+    x           /grp1/grp2/dset2
+    x           /grp1/grp2/grp3
+    x           /grp1/grp2/grp3/dset1
+    x           /grp1/grp2/grp3/dset2
+    x           /grp1/grp2/grp3/dset3
+    x           /grp10         
+    x           /grp10/dset4   
+    x           /grp10/dset5   
+    x           /grp10/elink_grp_circle
+    x           /slink_grp1    
+    x           /slink_grp10   
+    x           /slink_grp2    
+    x           /slink_grp3    
+
+dataset: </dset1> and </grp1/grp2/grp3/dset1>
+0 differences found
+dataset: </dset2> and </grp1/grp2/grp3/dset2>
+0 differences found
+dataset: </dset3> and </grp1/grp2/grp3/dset3>
+0 differences found
+EXIT CODE: 1