Since we can have several SVG-Edit graphics
on a page, SVG-Edit should assign unique IDs
to elements, and do so in a fashion that survives
re-editing.
To do this, we use a nonce, and record its value in
a custom se:nonce attribute on the <svg> element.
(Is there a better way?).
Also, preserve the custom se:connector attribute for
later editing purposes.
Most of the DOM manipulations can be done
before doing the AJAX call. This leaves
just the insertion of the MathML nodes in the
mrow for the AJAX callback function.
Also, make the stroke-width for the connector tool
default to 2.
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.
