[AC (pkgs)] Revert comint/shell changes

[Jerry James]

APPROVE COMMIT packages

I wrote:
> This patch reverts work over the last year on upgrading comint and
> shell.  I'll continue working privately to try to get the problems
> ironed out.  In the meantime, everyone else can use the previous
> version.

I have committed this patch.
-- 
Jerry James, Assistant Professor        james at xemacs.org
Computer Science Department             http://www.cs.usu.edu/~jerry/
Utah State University