General improvements

HTML:
- Added an initial conditional comment to prevent asset downloads from
being blocked.
(http://www.phpied.com/conditional-comments-block-downloads/)
- Added a fallback to load a local jQuery, if the CDN copy isn't
available
- Added "X-UA-Compatible" meta tag to force IE to use the most updated
rendering engine that it has available. This tag also enables Chrome
Frame if available.

CSS:
- Added HTML5 styles in `_standardise.scss` to support older browsers
when we start using HTML5 elements, as per `normalize.css` HTML5
Boilerplate
- Added default pointer styles for buttons and labels into
`_standardise.scss`, as per following
http://www.1stwebdesigner.com/design/snippets-html5-boilerplate/

JS:
- Separated plugin functions into a new `plugins.js`, as per HTML5
Boilerplate conventions
- Updated to use `Prepros` to concatenate `init.js` and `plugins.js`
into a single `init.min.js` file.
(http://alphapixels.com/prepros/docs/js-concat-minify.html)