Allow a pjax update to eval scripts returned in the body

This adds any scripts found in the reply body of a request to `document.body` unless a script tag with an equivalent source already exists in the DOM.

The script tags are inserted with the `async` flag set to false to maintain in-order evaluation.

As an unrelated cleanup, the `ignore` field of `component.json` was filled in to avoid polluting Bower-based installs.