commit-patch-buffer-in-directory: Use commit-patch script from the same directory

The missing link for distributing the package via ELPA

Still lots of noise from VCSes.

IE. Section D.8 of the elisp manual.

Thanks to Jonas Bernoulli <jonas@bernoul.li> for the push.

[commit-patch] Use --force when patching back to the clean version so if something goes wrong it doesn't ask interactive questions.

[commit-patch] Use --relative with "git diff" so that commit-partial doesn't silently fail when you in a subdirectory.

"git apply" seems to filter the diff so that only files within the current
directory (and its descendants) get applied. It (crazily) does this silently
and there doesn't seem to be an option to override this.

The other option would be to cd to the project root just before calling "git
apply" but I think it's more intuitive to diff from your current
directory--just cd to the root yourself if you want to see the whole
project's changes.

[commit-patch] Support svn 1.7 which apparently doesn't scatter .svn droppings in every subdirectory. (Thanks sneakypete81)

Prevent mercurial from adding/removing all files

Fixes #2

[commit-patch] Use Monotone's --without-header option instead of looking for diffs that are exclusively comments.

[commit-patch] Avoid running 'interdiff' and 'patch -R' also when the working patch is just a series of comment lines.

'mtn diff' will output three comment lines when there are no changes.
patch ignores them, so should we.