Ajax is asynchronous. Need to
sanitize in the callback function,
NOT when adding <math> to the DOM.
Need to unescape text for itex editor
window (since JQuery seems to take care
an 'extra' round of escaping).
Make the AJAX endpoint configurable (this could still be
done better).
Use POST, rather than GET for the AJAX request, so that
we don't have to worry about overly-long equations.
Add a Rack Metal itex endpoint.
Add an itex tool to SVG-Edit.
Disable the foreignObject tool
(at least, for now) as it doesn't
currently play nice with the itex tool.
