Deprecated functions

[Massimiliano Mirra]

A little heads-up for developers:

I've made the deprecation of old APIs somewhat self-documenting, now
calls to deprecated function will cause a message in the error console
to appear; it contains the name of the function, a stack trace that
will help you locate the caller, and advice on how to update the call.
They start with a timestamp, so that you can see for how long the
called function has been deprecated (and thus how likely it is that it
will go away soon).

-m