Fix port determination

[fixes #492]

We were doing a port job of determining when to add the port to a fully
qualified url and erred on the side of doing it all the time rather than
doing it only when necessary. This could cause problems.

This will also require a configuration change on the server to make sure
that the protocol in the configuration is properly 'https' rather than
'http'.
Better function name
Closes #666: Redirecting from /backpack/login when logged in
Return on redirect from login, and update backpack controller to call redirect(status, location) throughout
Merge pull request #754 from stenington/666-issue-of-the-beast

Redirecting from /backpack/login when logged in

closes #666
Add explanation of `remote_port`, add test.
Update descriptions in local-dist.js
Discover persona audience from request.

* We are going to be serving the backpack from two locations for a
  little while: beta.openbadges.org, and backpack.openbadges.org. This
  means that the audience needs to be derived from the request rather
  than from the server configuration, so that's what this commit does.

* Also, I've done a lot of refactoring to make things generally better,
  hopefully.
Fix some argument orders.
Merge pull request #757 from brianloveswords/492-fix-ssl-images

Fix port determination

fixes #492
Change variable name to be clearer.
Fix test to not overwrite conf.
Merge pull request #755 from brianloveswords/fix-persona-audience

Discover persona audience from request.
Fix version in package.json
Merge branch 'development' of github.com:mozilla/openbadges into development
Fix conmock to mirror express api.
Fix ballertime badge image location finding.
Separate logged in nav from login/logout
Active links are always blue, all nav links blue on hover
Remove stale app.locals