* Moves screen variables relating to Header to Header
* Adds a Header storybook entry
* Moves data-logo from Logo template to Header.mustache
* Updates UserLinks to use USER_LINK_PARTIALS
* Renames confusing SearchBox story names
* Updates package.json to use a static folder.
* Use mediawiki.org for sourcing mw-ui-button and mw-ui-icon styles
since deploys there come earlier
* Removes usages of ID selectors
Change-Id: I0e158fa7e62c56a50cfff497d75f0808effd1eed
