[PATCH] show-diff show deleted files as diff as well.
The ideas is that using the show-diff to generate the
patch including deleted and new file (in the next patch).
So we don't have to do the temp new file diff dance on the
script.
The cache index now contain enough information to generate
the whole patch. So the GIT SCM don't need separate command
for check out file to edit or delete. Just do the edit and
remove and GIT will generate the correct patch.
It still require tell GIT to add new files.