[svn-r3540] Purpose:

Feasibility improvement
Description:
    - Some member functions in class Exception can be called without
    an Exception instance exits, but because they are not static, they
    cannot.
    - Many exception throwings don't provide any information to callers.
Solution:
    - Add 'static' to several member functions in class Exception.
    - Added <class name::function name> to some exceptions thrown
	in H5File.cpp and H5FcreatProp.cpp.  I'm trying this for users'
	comments.  More information may be added later and to all
	exceptions.
    - Changed the comment line for emacs editor to:
	// C++ informative line for the emacs editor: -*- C++ -*-
      because... I'd rather not say that the code "may look like C" :-)
Platforms tested:
    Linux (gcc version egcs-2.91.66)

c++/src/H5DataSet.h

@@ -1,4 +1,4 @@
-// This may look like C code, but it is really -*- C++ -*-
+// C++ informative line for the emacs editor: -*- C++ -*-
 // Class DataSet inherits from AbstractDs and provides accesses to a dataset.
 
 #ifndef _H5DataSet_H