fix(errors): [2/2] Rename Exception to Error; remove from public API

BREAKING CHANGE:

Exceptions are no longer part of the public API. We don't expect that anyone should be referring to the Exception types.

ExceptionHandler.call(exception: any, stackTrace?: any, reason?: string): void;
change to:
ErrorHandler.handleError(error: any): void;

modules/@angular/router/src/shared.ts

@@ -30,4 +30,4 @@ export class NavigationCancelingError extends Error {
     this.stack = (<any>new Error(message)).stack;
   }
   toString(): string { return this.message; }
-}
+}