feat(playlist): move playlistSrv to playlist folder

public/app/features/playlist/playlistSrv.js

@@ -0,0 +1,56 @@
+define([
+  'angular',
+  'lodash',
+  'app/core/utils/kbn',
+],
+function (angular, _, kbn) {
+  'use strict';
+
+  var module = angular.module('grafana.services');
+
+  module.service('playlistSrv', function($location, $rootScope, $timeout) {
+    var self = this;
+
+    this.next = function() {
+      $timeout.cancel(self.cancelPromise);
+
+      angular.element(window).unbind('resize');
+      var dash = self.dashboards[self.index % self.dashboards.length];
+
+      $location.url('dashboard/' + dash.uri);
+
+      self.index++;
+      self.cancelPromise = $timeout(self.next, self.interval);
+    };
+
+    this.prev = function() {
+      self.index = Math.max(self.index - 2, 0);
+      self.next();
+    };
+
+    this.start = function(dashboards, timespan) {
+      self.stop();
+
+      self.index = 0;
+      self.interval = kbn.interval_to_ms(timespan);
+
+      self.dashboards = dashboards;
+      $rootScope.playlistSrv = this;
+
+      self.cancelPromise = $timeout(self.next, self.interval);
+      self.next();
+    };
+
+    this.stop = function() {
+      self.index = 0;
+
+      if (self.cancelPromise) {
+        $timeout.cancel(self.cancelPromise);
+      }
+
+      $rootScope.playlistSrv = null;
+    };
+
+  });
+
+});