CRM-20642 - ActivityFeed - Implement the include_case filter

In the "display options", this conditionally adds a checkbox "Show case
activities". Contingencies:

 * If the `ActivityFeed` is embedded within a case, then the `Activity.get` query filters on `case_id = civicrm#123`, and the option "Show case activities" is not available.
 * If "Show case activities" is enabled, then the `Activity.get` query does not filter on `case_id`. (Case and non-case activities are displayed.)
 * If "Show case activities" is disabled, then the `Activity.get` query filters on `case_id IS NULL`. (Only non-case activities are displayed.)

Depends on civicrm/civicrm-core#10451 for correct results

ang/civicase/ActivityControls.html

@@ -14,6 +14,12 @@
           <label for="act_control_overdue_first">{{ ts('Show overdue activities first') }}</label>
         </span>
       </li>
+      <li ng-show="!params.case_id">
+        <span>
+          <input type="checkbox" id="act_control_include_case" ng-model="displayOptions.include_case" />
+          <label for="act_control_include_case">{{ ts('Show case activities') }}</label>
+        </span>
+      </li>
     </ul>
   </div>
   <div class="btn-group btn-group-sm" data-toggle="buttons">

ang/civicase/ActivityFeed.js

@@ -2,7 +2,7 @@
 
   angular.module('civicase').config(function($routeProvider) {
     $routeProvider.when('/activity/feed', {
-      template: '<div id="bootstrap-theme" class="civicase-main" civicase-activity-feed="{filters:{case_id:{\'IS NOT NULL\': 1}}}"></div>'
+      template: '<div id="bootstrap-theme" class="civicase-main" civicase-activity-feed="{}"></div>'
     });
   });
 
@@ -32,7 +32,8 @@
 
     var displayOptions = $scope.displayOptions = CRM.cache.get('activityFeedDisplayOptions', {
       followup_nested: true,
-      overdue_first: true
+      overdue_first: true,
+      include_case: true
     });
 
     var involving = $scope.involving = {
@@ -141,6 +142,11 @@
       if (caseId) {
         params.case_id = caseId;
       }
+      else {
+        if (!displayOptions.include_case) {
+          params.case_id = {'IS NULL': 1};
+        }
+      }
       _.each($scope.filters, function(val, key) {
         if (val) {
           if (key === 'text') {