Merge branch 'ce-6145-extract-app-views-shared-issuable-2' into 'master'

CE: Resolve 2 "Extract EE specific files/lines for app/views/shared/issuable"

See merge request gitlab-org/gitlab-ce!19772

app/views/shared/issuable/_milestone_dropdown.html.haml

 - project = @target_project || @project
 - extra_class = extra_class || ''
 - show_menu_above = show_menu_above || false
+- selected = local_assigns.fetch(:selected, nil)
+
 - selected_text = selected.try(:title) || params[:milestone_title]
 - dropdown_title = local_assigns.fetch(:dropdown_title, "Filter by milestone")
 - if selected.present? || params[:milestone_title].present?