Merge from erc--emacs--22

Merge from erc--emacs--22

Merge from my ERC Emacs 22 integration branch.  The version is now "5.2
stable pre-release".  This will probably be the last change to the
version of ERC in Emacs 22 before the release, pending any bugfixes.  For
details on the changes, see the lisp/erc/ChangeLog file.

Note that ERC is now invoked with M-x erc, not M-x erc-select.  If you
were using the old `erc' function programmatically, use `erc-open'
instead.

Revision: emacs@sv.gnu.org/emacs--devo--0--patch-520
Creator:  Michael Olson <mwolson@gnu.org>