[PATCH] remote_function shouldn't escape string urls

When a URL specified as a hash is passed to remote_function, it (correctly) does not HTML-escape the URL in the output:

  remote_function(:url => {:action => "whatnot", :a => 10, :b => 20})

results in:

  new Ajax.Request('http://www.example.com/whatnot?a=10&b=20', {asynchronous:true, evalScripts:true})

However, when a string is specified, the URL is escaped:

  remote_function(:url => 'http://www.example.com/whatnot?a=10&b=20')

results in:

  new Ajax.Request('http://www.example.com/whatnot?a=10&b=20', {asynchronous:true, evalScripts:true})

This results in a problem when using named routes with remote_function in

The attached patch causes string URLs to no longer be HTML-escaped. It applies cleanly against master and 2-3-stable.

Note that this is similar to #2593 Add an :escape_url option to remote_function which adds an :escape_url option.