Fix Bug 2120 - h5copy: improve to copy an object into same HDF file
Description:
Merged from HDF5 trunk r20203.
Before the fix users can't copy an object (dataset or group) with
different name if input file (-i) and output file (-o) is same.
This feature would be useful to clone any object with different name and
reuse contents.
Tested:
jam (linux32-LE), amani (linux64-LE), heiwa (linuxppc64-BE), Cmake (jam)
6dd040b271