Undo js-escaping, when building redirect url for AJAX response

In In-Portal 5.2.0 JavaScript class FormManager was introduced. It allows to process any form on a page using ajax instead whole page submit.

To use it you must:

• register form on a page
• handle it's submit and pass it to FormManager instead
• wrap form processing event in AjaxFormHelper::transitEvent method call

If wrapped event requested a redirect to other, then current, page then instead of doing that redirect AjaxFormHelper::transitEvent method grabs redirect url and returns is to as 'redirect_to' parameter to FormManager class.
This gives a lots of space, since FormManager class can:

• redirect url to that url
• show page from that url in div/popup

Because of FormManager is JavaScript class and AjaxFormHelper is PHP class an url in 'redirect_to' parameter must not have "&" in it.
But it does and this results in all extra url parameters lost on the page, where redirect is made.