andSelf still needs cleanup

[pobocks]

There's a typo (lack of space in "maintain aninternal stack," and the description of the demo describes the old demo rather than the new one (my bad!).

Although looking at http://bugs.jquery.com/ticket/9800, it appears that other action might need to be taken. I looked through the code, and it is implemented as an alias of addBack - and addBack does take a selector. But addBack isn't documented in the api docs, as far as I can tell

I'm going to fix the docs so they're accurate - long term, should the andSelf docs be replaced with addBack docs, and a deprecation notice for andSelf?