annotate.tpl.html: avoid this.remove(): it crashes IE

Under IE 10, this.remove() raises an exception which is not
handled and stops the JavaScript interpreter.

Waiting for a more comprehensive groking of JavaScript, use a
hack to circumvent the problem with IE: replace the DOM object
to be replaced with an empty string.
Merge pull request #100 from bassosimone/fix-annotations-ie-bug

annotate.tpl.html: avoid this.remove(): it crashes IE