Iframetransport uses old mimetype style instead of handleAs

[guest]

0.9 Book appears to use the correct one.

http://dojotoolkit.org/book/dojo-porting-guide-0-4-x-0-9/io-transports-ajax

IFrame requests (dojo.io.iframe) To send an IO call using an IFrame (for instance, to send a file to the server), dojo.require("dojo.io.iframe"), and use:

• dojo.io.iframe.send()

Specific arguments for dojo.io.iframe calls:

• method: "POST". What type of HTTP method to use for the request. Valid values are "POST" (default) or "GET".
• handleAs: Valid values are text/plain, text/html, text/javascript, text/json, application/json. IMPORTANT: For all values EXCEPT text/html, The server response should be an HTML file with a textarea element. The response data should be inside the textarea element. Using an HTML document the only reliable, cross-browser way this transport can know when the response has loaded. For the text/html mimetype, just return a normal HTML document. NOTE: text/xml or any other XML type is NOT supported by this transport.

[James Burke]

I think this issue is saying that the Porting Guide page referenced above had a "mimetype" reference. If that is the issue, I just fixed the one reference on that page to mimetype and changed it to handleAs.