Add selection of images by railroad track

static/css/directives/repo-view/repo-panel-tags.css

@@ -25,6 +25,7 @@
 
   border: 2px solid black;
   border-radius: 50%;
+  cursor: pointer;
 }
 
 .repo-panel-tags-element .image-track-line {

static/directives/repo-view/repo-panel-tags.html

@@ -72,7 +72,7 @@
       </td>
       <td class="image-track" ng-repeat="it in imageTracks">
         <span class="image-track-dot" ng-if="it.image_id == tag.image_id"
-              ng-style="{'borderColor': it.color}"></span>
+              ng-style="{'borderColor': it.color}" ng-click="selectTrack(it)"></span>
         <span class="image-track-line" ng-class="trackLineClass($parent.$index, it)"
               ng-style="{'borderColor': it.color}"></span>
       </td>

static/js/directives/repo-view/repo-panel-tags.js

@@ -207,6 +207,12 @@ angular.module('quay').directive('repoPanelTags', function () {
       $scope.setTab = function(tab) {
         $location.search('tab', tab);
       };
+
+      $scope.selectTrack = function(it) {
+        $scope.checkedTags.checkByFilter(function(tag) {
+          return $scope.imageIDFilter(it.image_id, tag);
+        });
+      };
     }
   };
   return directiveDefinitionObject;