Set up header actions on click without JS, change style, etc.

• Set up header dropdowns, sidebar, and search bar to toggle on

click without JS.

• Changed style of dropdowns, sidebar, and search bar (e.g.,

different sidebar background color).

• Added search button to search bar.
• Added box-shadow to header and header search suggestions.
• Vertically centered images and text in header.
• Cleaned up some CSS. The end goal is that all rules in main.css

(or really main.less) should apply to all versions of the skin.
(More precisely, the goal is that very few rules in main.css are
superseded by rules in small.css, medium.css, or big.css. So, for
example, rules for an element that is only visible in small could
still be in main.css, assuming no rules in big.css and medium.css
supersede them). Up to this point, what sort of rules belong in
main.css hasn't been well defined. Hopefully this will make future
development easier, since it'll be easier to know what rules should
go in each file.

• Added unique IDs/classes that distinguish each header category

dropdown and the items inside.

• Added classes to li elements inside the user-info dropdown.
• Fixed search suggestions issue. On pages like

Special:Contributions, where multiple search suggestions elements
are present, Refreshed added the .header-suggestions class to the
first suggestions box. Now it adds it to the last suggestions box.

Change-Id: I4e94c92adbd40a42fad7f9d1b63db34646f7ad2e