Make the nav bar button float left.
Don't mute the event name in the mast-head.
Wrap the milestone under the date.

I did this using a definition list, which provides a nice indented wrapping by default. It also seems slightly more semantically correct.
Remove the event date from the timeline.

This is all over the place so no need to include it in the timeline itself.  @adrianbanks suggested the registration date is the one most visitors will be interested in, and I think I agree.
Move the Sessions link.

After the Home link, this is probably the most important thing, so it should go second.
Add a placeholder for an Agenda tab.

We don't have an agenda page yet, and I can't be bothered to create it right now. The link is there in the Razor layout page waiting to be enabled.
Fix the favicon.

The favicon wasn't displaying correctly in Firefox (favicons are tricksy beings!).  The fix is to give it an absolute URL; I have used the production URL because, well, it should always work, wherever you are...
Set a minimum width on the sidebar.

The text in the venue address and timeline was wrapping in an unfortunate manner (e.g., mid-road name, mid-date, etc.), so a simple min-width fix ensures that it's always given enough space to prevent the text from ever needing to wrap at all.  …and *breathe*.
Add an image_src link.

Apparently this works with embed.ly to enable Twitter Cards for our site
when someone posts a link to our site using their service. @adrianbanks
suggested it also works with Facebook, so seems like a good change to
make.

Also remove the second favicon link, most likely the result of a
copy-paste error.
Convert literal URLs to @Url.Content.

Not sure what advantage (or otherwise) this brings, but there we go.
Merge branch 'visual-design'

Fix a bunch of snags identified by Adrian earlier this evening.