Updates behavior of sequence navigation menu

Another step in [#51593657]. This makes all the activity links in the menu change the "active" activity, i.e. the one with the blue highlighting and the visible list of pages. Final step should be to get this behavior with the carets/arrows and the previous behavior with the text links.

https://www.pivotaltracker.com/story/show/51593657
Nav menu: caret opens page list, activity name is link

[#51593657]

https://www.pivotaltracker.com/story/show/51593657
Publish a sequence to the portal
Fix how the url for activities that are contained within a sequence.
rm vestigial portal library
Refactoring note: session/run/request key
Assets and CSS to support HAS footer

[#54535284] The HTML in `/docs/has-footer.html` actually needs to be put in the Project object describing the project. (I'll do that on staging and production when this gets deployed to those servers.) Logos, as of this commit, are just laid out at the bottom of the footer box.

https://www.pivotaltracker.com/story/show/54535284
Gemfile: add sketchily image_question_answer.rb: add annotation field.
Fix typo in image_question_answers runtime view. (sketchily) height %400
Remove unused toolbar and buttons in the svg editor.

[#53245137]
Gemfile changes: Bump Shutterbug, change sketchily to point at CC branch
Shutterbug: Use local rack service (same origin for SVG?)

[#53245137]
https://www.pivotaltracker.com/story/show/53245137
A student can see the snapshot as they annotate the image question answers.
Summary indents answer, strips tags from prompts

[#50555355]

https://www.pivotaltracker.com/story/show/50555355
Change made for upgrade of exception notifier gem to version 4.x.
Configured Shutterbug config to use Shutterbug running on heroku
Strips caption content as well as tags in summary

Doing a little better for [#50555355]

https://www.pivotaltracker.com/story/show/50555355
Fixing specs to expect image question annotations
Aligning image answers in activity summary

This should fix [#54716442]

https://www.pivotaltracker.com/story/show/54716442
Each activity lists its own pages and links them properly

Bugfix for [#51593657]

https://www.pivotaltracker.com/story/show/51593657