Added script template for contributors.

Added script template for use with mustache.js for rendering the dynamic
contributors.
Quick hack to check this works.
Quick hack to call the api from js
Added s=150 to the avatars.

Assumed the avatar URL returned by the GitHub API will always have
a querystring. It currently does, so I've just appended `s=150` onto the
end. When I tested it too, the last value for `s` wins, so if you
already have `s=80` already in the URL and we append `s=150` we'll get
150x150 pixel images.

Removed _Contributors.cshtml, as all the HTML for this has been moved
into the Mustache script template that sits in Views/Home/Index.cshtml.

I've added an octocat background image to the #contributors element so
that something is displayed while we're loading the contributors via the
API.

I've also updated the CSS for the contributors list, so that it displays
the same way as the current homepage is displayed.
Mustach template update, and CSS transitions.

When the contributors are loaded via Ajax, CSS transitions are used to
fade out the octocat image and fade in the contributors.

Mustache template updated to handle cases where a user doesn't have
their Twitter username associated with their GitHub account.
Compact CSS rule formatting applied.
LESS files changes made directly to global.css.

Checked out global.css from commit 5fe162a, then added the changes made
to global.less directly to global.css.

Increased the width of the dl lists on the plugins page to fix a layout
issue.
Updated log4net for Glimpse.package