Please tag revision 103620 as package-el-compat23 before git transition

[Noam Postavsky]

Revision 103620 (aka 1a0a666f941c99882093d7bd08ced15033bc3f0c in git
mirrors) is referred to in a few places because it's the last version
of package.el that can work with Emacs 23. Since the transition to git
will change revision numbers/hashes it would be nice to have a stable
identifier in place before the transition.

Thanks.