Rename: _title_etc => _common_edition_attributes

www.agileplannerapp.com/boards/173808/cards/5629

This partial contains many fields which are common
across formats, hence a more descriptive name.
Convert activity forms to edition's attributes

www.agileplannerapp.com/boards/173808/cards/5629

Editors have reported issues with the existing
pattern of saving the edition form via AJAX before
doing a transition. Due to these multiple submissions
we suspect that on rare occations transition happens
but edition doesn't get saved.

Editors assume that when a transition happens, the
edition form changes are saved, and don't think of
it as a 2 step process.

This change ensures that transition is performed
using attributes within the edition form, which
ensures that we save the edition and perform the
transition in a single request.
Split button helpers into a separate file

www.agileplannerapp.com/boards/173808/cards/5629
Removing unused placeholder attribute

www.agileplannerapp.com/boards/173808/cards/5680

couldn't find usages for that field in views.
Adding back activity form generation logic

www.agileplannerapp.com/boards/173808/cards/5629

Some scenarios need just the activity to be performed
without saving edition changes. Hence accommodating
that within the activity helper.
Updating modal title and button text

www.agileplannerapp.com/boards/173808/cards/5629

The earlier text was appropriate as button text,
but not as modal title or modal button text.

Also, adding a useful bit of help text to tell
editors that their changes are not lost when
they make transitions.
Controller changes to transition during update

www.agileplannerapp.com/boards/173808/cards/5629

also, saving the states and their labels in the
Edition model so they can be referred from the
helper as well as controller. modeling events
and its human readable format as a Hash, because
that's more appropriate.
Fix tests related to Edition workflow
Cancel scheduled publishing should not be inlined

www.agileplannerapp.com/boards/173808/cards/5629

... with the edition form. it needs to be submitted
to editions#progress because submitting the edition
will return error: Edition scheduled for publishing
can't be edited.

also, this action is triggered from a view where
edition fields are locked, so we don't want to
save edition changes while transitioning.
Editions don't need to be saved via AJAX

www.agileplannerapp.com/boards/173808/cards/5629

This was required earlier to save an Edition when
making an edition transition. Now that transition
parameters are submitted as edition fields, we do
not need to save the edition form via AJAX before
transitioning to another state.
Replace fake 'Save' button with a real one

www.agileplannerapp.com/boards/173808/cards/5629

This allows us to submit editions without using JS.
Changing buttons to links

www.agileplannerapp.com/boards/173808/cards/5629

... so that clicking them doesn't submit the edition
form, instead opens a modal
Converting more buttons to links

www.agileplannerapp.com/boards/173808/cards/5629

Buttons with type=submit are being used within forms
to submit the edition transition and edition form.
Rectifying this issue.
Renaming transition to activity

www.agileplannerapp.com/boards/173808/cards/5629

... to keep the naming consistent all across.
Correcting case on button text

www.agileplannerapp.com/boards/173808/cards/5629

... and activity dialog copy.
Merge pull request #251 from alphagov/save-and-transition-in-one-go

Save and transition editions in one go