when.d.ts - add ability to return primitive from catch callback

when/when-tests.ts

@@ -164,6 +164,9 @@ promise = when(1).catch((err: any) => when(2));
 promise = when(1).catch((err: any) => err.good, (err: any) => 2);
 promise = when(1).catch((err: any) => err.good, (err: any) => when(2));
 
+promise = when(1).catch(Error, (err: any) => 2);
+promise = when(1).catch(Error, (err: any) => when(2));
+
 //TODO: error constructor predicate
 
 promise = when(1).otherwise((err: any) => 2);

when/when.d.ts

@@ -174,7 +174,7 @@ declare module When {
 
         // Make sure you test any usage of these overloads, exceptionType must
         // be a constructor with prototype set to an instance of Error.
-        catch<U>(exceptionType: any, onRejected?: (reason: any) => Promise<U>): Promise<U>;
+        catch<U>(exceptionType: any, onRejected?: (reason: any) => U | Promise<U>): Promise<U>;
 
         finally(onFulfilledOrRejected: Function): Promise<T>;