trim templates to prevent conflicts with jQuery (fix issue #323)

Hey, I've been looking into issue #323, that's the fix I came up with. Although, I'm not sure this should be added into core; the problem is that the template returned by `fetch` is an invalid _jQuery allowed_ DOM string to generate a new elements.

This is directly related to `el: false` as normal view will only delegate the insertion of new element to `innerHTML` which allow newline and whitespace. `jQuery` constructor does not, so this example only fail when generating a new DOM fragment.

What do you think? cc @tbranyen @jugglinmike