Since there were no more comments on my previous reply I will pick the
option I like best :) The performance is anyway very good regardless
which option I take.

Now for another matter: documentation. I've been thinking about where to
best describe this new feature. It does not need a very length
description I think, but we should mention it in the manual. Here is the
current "menu" for Abbrevs:

* Abbrev Concepts       Fundamentals of defined abbrevs.
* Defining Abbrevs      Defining an abbrev, so it will expand when typed.
* Expanding Abbrevs     Controlling expansion: prefixes, canceling
expansion.
* Editing Abbrevs       Viewing or editing the entire list of defined
abbrevs.
* Saving Abbrevs        Saving the entire list of abbrevs for another
session.
* Dynamic Abbrevs       Abbreviations for words already in the buffer.
* Dabbrev Customization  What is a word, for dynamic abbrevs.  Case
handling.

Any thoughts on this?

Also, once the documentation is done, what would be the steps, in git,
to get this into Emacs? Are we using feature branches? Do people commit
to master? Or can I send a patch by e-mail? (less risk of me messing
up...)

Thanks!