Introduce two new type aliases - LinkFnControllerType and RequireType.

This allows users to write callbacks using those aliases instead of the
full type.

Having convinient aliases is required for having AngularJS in TS work
better with strictFunctionTypes flag on.
see: angular/angular.js#16617

Also having them next to each other shows the symmetry between the
require and controller param better.

types/angular/index.d.ts

@@ -2075,11 +2075,15 @@ declare namespace angular {
             scope: TScope,
             instanceElement: JQLite,
             instanceAttributes: IAttributes,
-            controller?: IController | IController[] | {[key: string]: IController},
+            controller?: LinkFnControllerType,
             transclude?: ITranscludeFunction
         ): void;
     }
 
+    type RequireType = string | string[] | {[key: string]: string};
+
+    type LinkFnControllerType = IController | IController[] | {[key: string]: IController};
+
     interface IDirectivePrePost<TScope extends IScope = IScope> {
         pre?: IDirectiveLinkFn<TScope>;
         post?: IDirectiveLinkFn<TScope>;
@@ -2116,7 +2120,7 @@ declare namespace angular {
          * @deprecated
          */
         replace?: boolean;
-        require?: string | string[] | {[controller: string]: string};
+        require?: RequireType;
         restrict?: string;
         scope?: boolean | {[boundProperty: string]: string};
         template?: string | ((tElement: JQLite, tAttrs: IAttributes) => string);