[14] use namespaced polyfills

src/utils/cache.ts

@@ -1,6 +1,6 @@
 // import from npm
 import Promise = require("bluebird");
-import "core-js";
+import * as Map from "core-js/library/fn/map";
 import { assignIn, forEach } from "lodash";
 
 // declare an interface for the object that is

src/utils/get-dom-marker-icon.ts

@@ -1,4 +1,4 @@
-import "core-js";
+import * as Map from "core-js/library/fn/map";
 
 /**
  * Map for HTML strings against H.map.DomIcon instances

src/utils/get-link.ts

@@ -1,5 +1,5 @@
 // import from npm
-import "core-js";
+import * as Map from "core-js/library/fn/map";
 import { assignIn } from "lodash";
 
 // declare an interface for the object that is

src/utils/get-marker-icon.ts

@@ -1,4 +1,4 @@
-import "core-js";
+import * as Map from "core-js/library/fn/map";
 
 /**
  * Map for image URL strings against H.map.Icon instances

src/utils/mixin.ts

@@ -1,4 +1,5 @@
-import "core-js";
+import * as Reflect from "core-js/library/fn/reflect";
+import * as Symbol from "core-js/library/fn/symbol";
 
 export function mixin(behaviour: any, sharedBehaviour: any = {}) {
   // these keys reflect the behaviour that is to be attached to class instances