Logging in debug and release builds

[Alex Bligh]

> I've extended my previous example and attached it to the end of this 
> email. Everything is compiled in release mode with -O2. Running this 
> example with the wxLogDebug call active in the inner loop,

[it gets slower]
>       wxLogDebug (wxT ("count: %s"), wxString::Format ("%d", 
> count).c_str ());

Well, that has side effects. It goes calling wxString::Format().

Alex