Fixed issue #58

Hi,

I've been using Dropkick for a while and ran into a problem described in issue #58 (https://github.com/JamieLottering/DropKick/issues/58)

The problem is that if one of the labels contains '<' and '>', it is displayed as an html element instead of just simple text.

This is an example that reproduces the error: http://jsfiddle.net/FRSMM/ (both dropdowns work OK without dropkick: http://jsfiddle.net/FRSMM/1/)

The solution I found was to use ```.html()``` to get the label text instead of ```.text()```, because the former returns the html encoded version, which is what we need.

This is how it works after the fix: http://jsfiddle.net/FRSMM/2/


Thanks for this great library!