generates a new AJAX request to the wanted URL, in order to retrieve
a fresh instance of the webform.
Fixes #1489826 .

Fix JS use of each(), to apply the appropriate AJAX handlers to confirmation page's "Go back to the form" link.

Conflicts:
	webform_ajax.module

This reverts commit e3ffffb2.

Merge was made too early.
This reverts commit afb1dd2b, reversing
changes made to 7962388a.

Conflicts:

	webform_ajax.module

Conflicts:
	js/webform_ajax.js
	webform_ajax.module

Ensure that a wrapper is around our AJAX manipulated form, and that it has a unique and persistant id.

Conflicts:
	webform_ajax.module

Also adds a setting to show confirmation page or not when no redirection is set.
Fixes #1475918.