Append the throbber to the entire window, instead of a separate div.
Render a proper response from the dummy app
No longer using our own icon, but one included in TinyMCE
Let the submit button get the "primary button" styles
Starting to worry about TinyMCE. The missing name attributes are fixed
Clean up iframe naming
Not using the progress-container I made, but we might shove errors there
Need event listeners on the iframe
Partial response and error handling
Get a decent submit handling
Cosmetics