Document the uselessness of native change events when using widgets

[scottgonzalez]

All widgets that build on top of form controls kill the ability to use the native change event since we programmatically change the field's value. We should mention this in the docs for each widget.

[tjvantoll]

jquery/contribute.jquery.org#18

[mikesherov]

@tjvantoll , This is good in wontfix in contribute, but this should also be mentioned in the regular docs as well, as @scottgonzalez describes.

[tjvantoll]

Alright I can take care of that as well. Thoughts on the best place to put this? I was thinking in the "Additional Notes" section of each widget.

[scottgonzalez]

I think the Additional Notes section works well. We can have a generic note that we include for each widget that needs it.

[tjvantoll]

19af64c