Fix and improve
Description:
- Put functions that are common to H5File and Group into a
prototype class, CommonFG. I didn't do that before because
of the fear of the consequences of multiple inheritance, since
H5File and Group already inherit from different super classes.
I recently read a C++ book and learned to use MI more safely.
This change reduced some more of code redundancy.
- Added missing const to some function parameters
Platforms tested:
Solaris/CC 5.0 (arabica)
1aec17231d