- rake locomotive:upgrade:rename_collections

- locales updates (en / fr)

  - theme_assets.images => theme_assets.image_picker
  - assets => content_assets
  - EditableXXX => Locomotive::EditableXXX (in mongodb)
  - content_types:
    - category => select
    - highlighted_field_name => highlighted_field_id (label_field_id)
    - api_enabled => public_submission_enabled
    - api_accounts => public_submission_accounts
  - contents (content_entries now)
    - _position_in_list => _position
  - api_contents:
    - url => entry_submissions
    - params[:content] => params[:entries]


collection, selector = Locomotive::ContentType.collection, Locomotive::ContentType.criteria.selector
collection.update selector, { '$rename' => { 'contents_custom_fields' => 'entries_custom_fields' } }