DotNetNuke 3.1 Upgrade

I've installed DotNetNuke 3.1 on my site, here. 

I still a lot of work to do to make everything work, but I just worked
through one problem and thought the solution might be useful to

The problem is that after the upgrade, the FreeTextBox control doesn't
work, so you can't edit anything using the HTML editor.  Instead,
you get this:

FreeTextBox has not been correctly installed. To install FreeTextBox either:
(1) add a reference to FtbWebResource.axd in web.config:
<add verb="GET"
type="FreeTextBoxControls.AssemblyResourceHandler, FreeTextBox" />

(2) Save the FreeTextBox image and javascript files to a location on your website and set up FreeTextBox as follows
<FTB:FreeTextBox id="FreeTextBox1" SupportFolder="ftbfileslocation"
JavaScriptLocation="ExternalFile" ButtonImagesLocation="ExternalFile"
ButtonImagesLocation="ExternalFile" runat="server" />

The problem, in my case, is that the HTML being generated referenced
the JavaScript files for FTB in /aspnet_client/FreeTextBox and those
files didn't exist there.  The solution is to figure out where
/aspnet_client maps to, and copy the files from your DotNetNuke's
Providers\HtmlEditorProviders\Ftb3HtmlEditorProvider\ftb3 directory
into aspnet_client\FreeTextBox.  That solved it for me.