Use govuk_template

This updates all the layouts here to use [govuk_template](https://github.com/alphagov/govuk_template).

Some things that have changed as a result of this:

* Replaced all cookie access functions with a single set (provided by govuk_template).
* Removed normalize - This wasn't adding much, and was breaking things when included after basic (which resets lots of it anyway)
* The search toggle button (mobile only) is now in a different location in the dom.  This has required updating some of the styles to handle this

### What does [govuk_template](https://github.com/alphagov/govuk_template) provide?

It provides a minimal template that should be suitable for use everywhere (including exemplars).  Including:

* Base header - just the Crown, and GOV.UK text, no search box, with hooks to add extra bits
* Base footer - no section links, no support links; just the copyright and licence stuff
* Some default global styles (pretty much just basic and accessibility)
* The IE JS hacks to make old IE work with html5 etc
* The font files (eot and woff), and css to setup the @font-face