[svn-r8576] Purpose:

Add more C++ wrapper and documentation - incrementally check-in

Description:
    Added doxygen documentation to:
        H5DataSet.cpp
        H5DataSpace.cpp
        H5CommonFG.cpp

    and a wrapper for H5Rcreate to H5Object.* with tests will be added
    later.

    There are more documentation need to be added to these files but
    to preserve the changes, I check them in now.

Platforms:
    SunOS 5.7 (arabica)
    Linux 2.4 (eirene)


Misc. update:

c++/src/H5Object.h

@@ -85,6 +85,9 @@ class H5_DLLCPP H5Object : public IdComponent {
 	void removeAttr( const string& name ) const;
 	void removeAttr( const char* name ) const;
 
+	// Creates a reference to a named H5 object in this object.
+	void* Reference(const char* name, H5R_type_t ref_type, DataSpace& dataspace) const;
+
 	virtual ~H5Object();
 
    protected: