Remove "alternate title" field from publisher

This removes the functionality to create and edit alternate titles for
editions within publisher. The intention is to get this change
deployed first before making an export of the data before it's finally
removed from the respective dependencies (govuk_content_models) and
database.

Story: https://www.agileplannerapp.com/boards/173808/cards/8145
Add task to export editions that have an alternative title
Reintroduce previous important note workflow

Previously users could easily append to existing important notes. When
updating the important note model it wasn’t clear whether this was a
user need or an artefact of the implementation. It is a need — users
are often appending information to the end of an existing note (eg 2i
user and schedule info)

* Prepopulate important note field with existing note
* If the user blanks the field resolve the note (be consistent with old
behaviour)
Remove verb and quotes from edition titles

* Viewing “…” is unnecessary
Simplify publication table title

* Remove extraneous quotes and nouns
Merge pull request #294 from alphagov/simplify-titles

Simplify page titles
Scroll to bottom before clicking "Add new part" in integration tests

Publisher has a set of common workflow buttons that sit within a bar
that's fixed to the bottom of the browser's window. This bar gets in
the way of Poltergeist "seeing" elements we want to click on.

To get around this there are three options:

1. Scroll to the bottom of the page and then click the link
2. Find the element on the page and trigger the "click" event
3. Restyle the page so that it doesn't have a fixed bar

For the purposes of this story, option 3 isn't realistic as it's going
to take a little more time and will require more conversations. Option
2 reads cleaner in terms of code, but takes longer to run on
average (tens of seconds longer) compared to option 1 where scrolling
to the bottom of the page is a fast action for WebKit.

This change goes with option 1 but tries to minimise the exposure of
this to a single helper method so that it can be refactored out later.

Please don't judge me too much for this :see_no_evil:
Merge pull request #292 from alphagov/remove-alternate-title-functionality

Remove alternate title functionality
Link to zendesk automatically

Notes often refer to zendesk tickets, it’s useful to link these
references to the ticket. Link commonly used patterns such as “zen
1234” and “zendesk ticket #1234”.
Move html_safe closer to source
Use link_to helper for generating zen links
Merge pull request #296 from alphagov/zen-ticket-links

Link to zendesk tickets from edition notes automatically
Merge pull request #293 from alphagov/important-notes-workflow

Reintroduce previous important note workflow