Pulling from a packed repository over dumb transport without the
server info file fails, so run update-server-info automatically
after a repack by default.  This can be disabled with the '-n'
flag.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Sure, "install" will default to installing it executable anyway, but
this is the right thing to do.

It sets up the normal git environment variables and a few helper
functions (currently just "die()"), and returns ok if it all looks like
a git archive.  So use it something like

	. git-sh-setup-script || die "Not a git archive"

to make the rest of the git scripts more careful and readable.

This means that the .git/objects/pack directory is also rsync'able,
since the filenames created there-in are either unique or refer to the
same data.

Otherwise you might not be able to pull from a directory that is partly
packed without having to worry about missing objects due to pack-file
name clashes.