New release mechanism, merge with Emacs

[Kai Grossjohann]

I've now adapted configure.ac and Makefile.in to use a different
mechanism for syncing the Emacs repository.  The old method was to
first make sure that all changes in Emacs' repository have been
transferred into the Tramp repository, then to just copy the files.

The new method is to make a patch between the last-synced version and
the to-be-synced version, which is then applied to a working copy of
the Emacs repository.

I've used this to sync the Emacs repository with 2.0.40.

Kai