[WIP] typeahead.js bloodhound support

Implemented typeahead.js [v0.10.x](https://github.com/twitter/typeahead.js/blob/master/CHANGELOG.md#0100-february-2-2014) which introduces a major API change.

The implementation is not feature-complete, currently the `Bloodhound` engine only supports simple remotes, due to https://github.com/l0rdn1kk0n/wicket-jquery-selectors/issues/6


@martin-g i moved the `getCallbackUrl()` call to the `onBind()` to remove the side-effect in the `getFunction()` call.