Deprecate Boolean attrHooks such as checked, selected

[dmethvin]

In jQuery 1.6.1 we put in some hooks to continue the queasy automagical relationship between certain attributes and properties that pre-1.6 versions of jQuery used.

We should deprecate the special hooks that allow things like .attr("checked", true) and continue the education that .prop("checked", true) is the correct method.

[dmethvin]

One issue with deprecating these is that there is the sneaky use of the attrHooks in the $(html, props) signature. So if we removed the hooks, this would break:

$("<input type=checkbox>", {
    "checked": true,
    click: function(){ alert("checked "+this.checked); }
});

Everything in that signature is a horrible rats nest of special cases, since it recognizes a small subset of event names and passes everything else through to .attr(). gibson042 pointed out that we could have another list of special cases for things that really should go through .prop() instead, or we can just deprecate the use of attrHooks here as well and intercourse the consequences, or we can deprecate the $(html, props) signature (in my dreams).

[timmywil]

I think we can deprecate this, but not remove until 1.9 or even 2.0. The most likely solution, which I am fine with, is to add prop() to the html shortcuts.

[dmethvin]

Just need a docs change for 1.8