Prompt with select

Implemented prompt with select list. Default functionality is untouched, however if you pass last argument as an object to bootbox.prompt() it will determine what to do. I also make some bootstrap 3.0.0 specified fixes to core. I did also add necessary tests for this functionality, hope you like it.

Basic example below:

bootbox.prompt("Select prompt", "Cancel", "OK", function(result) { showResult(result); }, { type: "select", options: [{value: 1, text: 'foo'},{value: 2, text: 'bar'}] });

And more examples: http://jsfiddle.net/Gzagv/

Also note that additional prompt types are easy to add after this.