Dragscroll possible, scroll the screen with the mouse at desktop view

- click on a empty list area and drag the view left/right to scroll

client/components/boards/boardBody.jade

@@ -18,7 +18,7 @@ template(name="boardBody")
   else
     .board-wrapper(class=currentBoard.colorClass)
       +sidebar
-      .board-canvas.js-swimlanes(
+      .board-canvas.js-swimlanes.dragscroll(
         class="{{#if Sidebar.isOpen}}is-sibling-sidebar-open{{/if}}"
         class="{{#if MultiSelection.isActive}}is-multiselection-active{{/if}}"
         class="{{#if draggingActive.get}}is-dragging-active{{/if}}")

client/components/boards/boardBody.js

@@ -1,5 +1,6 @@
 import { ReactiveCache } from '/imports/reactiveCache';
 import { TAPi18n } from '/imports/i18n';
+import dragscroll from 'dragscroll';
 
 const subManager = new SubsManager();
 const { calculateIndex } = Utils;
@@ -219,6 +220,7 @@ BlazeComponent.extendComponent({
       boardComponent.openNewListForm();
     }
 
+    dragscroll.reset();
     Utils.setBackgroundImage();
   },
 

client/components/cards/minicard.jade

@@ -1,5 +1,5 @@
 template(name="minicard")
-  .minicard(
+  .minicard.nodragscroll(
     class="{{#if isLinkedCard}}linked-card{{/if}}"
     class="{{#if isLinkedBoard}}linked-board{{/if}}"
     class="{{#if colorClass}}minicard-{{colorClass}}{{/if}}")

client/components/lists/listHeader.jade

@@ -1,5 +1,5 @@
 template(name="listHeader")
-  .list-header.js-list-header(
+  .list-header.js-list-header.nodragscroll(
     class="{{#if limitToShowCardsCount}}list-header-card-count{{/if}}"
     class=colorClass)
     +inlinedForm