[svn-r8269] Purpose:

Cleaning up warnings

Description:
    Many exception constructors have warnings about reference to temporary
    location because of the parameter initialization, for example,
    "const string& var = 0."

Solution:
    Changed "string&" parameters to pass by value for these constructors.
    Consequently, passing string by value also takes care of char pointers
    so the overloaded constructors for char pointers are then removed.
    Also, instead of setting Exception::detailMessage to null string, I
    set it to DEFAULT_MSG ("No detailed information provided") by default.

Platforms:
    SunOS 5.7 (arabica)
    Linux 2.4 (eirene)
    IA-64 (titan)

c++/src/H5Group.cpp

@@ -138,7 +138,7 @@ void Group::p_close() const
 }
 
 // Throw file exception
-void Group::throwException(const string& func_name, const string& msg) const
+void Group::throwException(const string func_name, const string msg) const
 {
    string full_name = func_name;
    full_name.insert(0, "Group::");