Fix build for (S)XEmacs.

Fix build for (S)XEmacs.

This changeset hopefully fixes all the problems and quirks I've
encountered when trying to build Gnus with SXEmacs.

	* .gitignore: Add ++log

	* lisp/imap.el: New.  Actually, bring back the old. imap.el no
	longer exists in Gnus because it is already in GNU/Emacs, but
	(S)XEmacs doesn't have it.

	* lisp/smiley.el: Replace with Wes' version.  It is still better
	than the GNU version.

	* lisp/gnus-start.el: Wrap require gnus-cloud in a #'ignore-errors
	as it is currently removed from the build via dgnushack.el

	* lisp/dgnushack.el (dgnushack-compile): Don't compile libs that
	are present in the mail-lib, ecrypto, net-utils, and text-mode
	XEmacs packages if they are installed.

Signed-off-by: Steve Youngs <steve@sxemacs.org>