[StGit] Emacs mode merge request

Catalin, can you please merge the following series from
git://github.com/gustavh/stgit.git "proposed" branch.
All the patches are small, incremental improvements and bug fixes to
the Emacs mode.

199cec3 tutorial: Very minor typo fixes in the Emacs section
939ff13 stgit.el: Add stgit-{git,stg}-program variables
e23eb46 stgit.el: Rearrange customizations a bit
5be0bca stgit.el: Add "Customize StGit" menu entry
cde79c7 stgit.el: Improve how "t h" mode finds old commits
160b5bf stgit.el: Make C-{up,down} move between groups of patches
b8738ed stgit.el: Add a few links to some customization variables
d528462 stgit.el: Repair ! for historical commits
16e96c0 stgit.el: Honor stgit-find-copies-harder in stgit-diff-range
65f3ffa stgit.el: Honor stgit-find-copies-harder when showing entire patches
108e5c8 stgit.el: Fix showing diff in file that has been both copied
and modified

The branch is based on your "proposed" branch (53055a56).

Somewhat unrelated, whom should I talk to about getting the Emacs mode
into the Debian package?
I think the Emacs mode ought to go into the 'stgit' package rather
than 'stgit-contrib', but some may disagree...

Thanks,
 Gustav