fix(typings): test our .d.ts with --noImplicitAny

This matches how DefinitelyTyped tests it, so we are
one step closer to publishing the same file we generate.

See #3195

modules/angular2/src/forms/directives/checkbox_value_accessor.ts

@@ -54,6 +54,6 @@ export class CheckboxControlValueAccessor implements ControlValueAccessor {
     return isPresent(this.cd.control) ? !this.cd.control.valid : false;
   }
 
-  registerOnChange(fn: (_) => {}): void { this.onChange = fn; }
+  registerOnChange(fn: (_: any) => {}): void { this.onChange = fn; }
   registerOnTouched(fn: () => {}): void { this.onTouched = fn; }
 }

modules/angular2/src/forms/directives/default_value_accessor.ts

@@ -60,7 +60,7 @@ export class DefaultValueAccessor implements ControlValueAccessor {
     return isPresent(this.cd.control) ? !this.cd.control.valid : false;
   }
 
-  registerOnChange(fn: (_) => void): void { this.onChange = fn; }
+  registerOnChange(fn: (_: any) => void): void { this.onChange = fn; }
 
   registerOnTouched(fn: () => void): void { this.onTouched = fn; }
 }