RFC: Adding BBDB to Emacs core

[Thomas Fitzsimmons <fitzsim@fitzsim.org>]

Hi,

Now that BBDB is copyright clear and available in GNU ELPA, thanks to
Roland Winkler, I'd like to see what people think about also adding it
to Emacs core.

While maintaining EUDC in Emacs core, I've encountered many references
to BBDB that are unresolved.  The only reason for this, as far as I can
tell, is that historically BBDB's copyright status didn't allow it to be
included in core.  Otherwise it probably would have been included all
along.  Now it's possible to fix this properly.

I've started an integration attempt on the scratch/eudc-bbdb-3 branch.
I merged a recent version of BBDB from GNU ELPA into lisp/bbdb, then I
resolved references to BBDB in EUDC.  For example, we can remove things
like:

   (declare-function bbdb-record-phones "ext:bbdb" t) ; via bbdb-defstruct

and apply changes like:

--- a/lisp/net/eudc-export.el
+++ b/lisp/net/eudc-export.el
@@ -31,10 +31,8 @@
 ;;; Code:
 
 (require 'eudc)
-
-;; NOERROR is so we can compile it.
-(require 'bbdb nil t)
-(require 'bbdb-com nil t)
+(require 'bbdb)
+(require 'bbdb-com)
 
 (defun eudc-create-bbdb-record (record &optional silent)
   "Create a BBDB record using the RECORD alist.

This makes the code cleaner and easier to maintain.  We can also rely
only on the version of BBDB in GNU Emacs (or a later one in GNU ELPA)
and so all the BBDB < 3 compatibility code can be deleted without risk
of breaking people's package sets (BBDB >= 3 auto-converts BBDB < 3
databases to the updated format).

I think applying this same type of effort to the other BBDB-dependent
core packages would simplify them too.

I'd like BBDB to become the default out-of-the-box local contact
management library for GNU Emacs, in particular so that Gnus/EUDC/BBDB
work together to provide email completion and snarfing out-of-the-box,
without extra configuration or package installation.

Thoughts?

Thomas