Added ability to clear milestone/assignee during bulk update

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/helpers/issues_helper.rb

@@ -68,4 +68,12 @@ module IssuesHelper
       false
     end
   end
+
+  def bulk_update_milestone_options
+    options_for_select(["None (backlog)", nil]) + options_from_collection_for_select(project_active_milestones, "id", "title", params[:milestone_id])
+  end
+
+  def bulk_update_assignee_options
+    options_for_select(["None (unassigned)", nil]) + options_from_collection_for_select(@project.team.members, "id", "name", params[:assignee_id])
+  end
 end

app/views/projects/issues/_issues.html.haml

@@ -6,8 +6,8 @@
         = form_tag bulk_update_project_issues_path(@project), method: :post  do
           %span Update selected issues with  
           = select_tag('update[status]', options_for_select(['open', 'closed']), prompt: "Status")
-          = select_tag('update[assignee_id]', options_from_collection_for_select(@project.team.members, "id", "name", params[:assignee_id]), prompt: "Assignee")
-          = select_tag('update[milestone_id]', options_from_collection_for_select(project_active_milestones, "id", "title", params[:milestone_id]), prompt: "Milestone")
+          = select_tag('update[assignee_id]', bulk_update_assignee_options, prompt: "Assignee")
+          = select_tag('update[milestone_id]', bulk_update_milestone_options, prompt: "Milestone")
           = hidden_field_tag 'update[issues_ids]', []
           = hidden_field_tag :status, params[:status]
           = button_tag "Save", class: "btn update_selected_issues btn-small btn-save"