Idea for determining what users use

[Richard Stallman]

We have no good way to determine if anyone still uses a feature.
Maybe we can create one.

Imagine a function called note-feature-used.
You call it like this:  (note-feature-used 'foo "Foo").
The first time you call it, it sends mail to
address@hidden with subject Foo,
asking you for permission to send it,
and it records (setq foo t) in your .emacs file.
If you call it again, it does nothing.

We could put these calls into various files and functions 
in order to find out (after the next release) whether anyone uses them.