Transifex translation support
Create 1.0 branch for 3.0.x compatability
BUG add $allowed_actions for both DMSDocumentAddController and DMSUploadField
Update composer.json to indicate 3.1 compat
Fixed composer constraint to allow for RC releases (composer fixed its tilde behaviour now)
Remove 3.0 builds from DMS master, no longer supported
Fix deprecation warnings for master
3.1 compat (controller code)
Fix #14 - Shortcode download link fixed
Add allowed_actions to make it work for 3.1
FIX Don't show the upload field when inappropriate

This fix is quite ugly, but in theory, it's fine. By ugly,
  I mean the interface is kind of weird without it.
Because 3.1 allows uploading when a DataObject doesn't exist,
  we need to override the new defaults to not allow such if
  the DO isn't saved yet.
FIX #25 - documentautocomplete need allowed_action
FIX #29 - 'linkdocument' needed adding to allowed_actions
Compatbility with master - allowed_actions private
Extend content controller to make sure the correct stage is used.

The staging system is initialised inside ContentController::init(). As
the DMS serving bypassed this, the stage was not set correctly, meaning
permissions were not always correctly applied.
BUG: Fix the action buttons not rendering on upload.

Due to escaping API changes, a HTMLText instance was being incorrectly
casted to JSON.
BUG: Share session namespace with CMS main when adding documents.

The changes to the session management in 3.1 mean that editing when
uploading a document no longer worked as the page ID was not correctly
managed in the session. This addresses that issue by sharing a session
state with CMSMain.
Move shortcode handling into a new class.
NEW: Add metadata to DMS links.

Shortlink links are now augmented with data attributes containing the
file extension and size.
BUG: Fix access to documents on the staging site.

The DMS document controller had been changed to subclass ContentController
to correctly initialise the versioned stage. However, this had the side
effect of preventing access to documents when the "Stage" stage
was selected.

ContentController::init() calls the SiteTree::canViewStage() method, which
controls access when on the stage. However, since the data record was
non-existant, the method would always return false, preventing access to
documents.

This fix removes the subclassing of ContentController and just directly
initialises the versioned stage.