fix(build): add missing return types now enforced by linter

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

@@ -123,7 +123,7 @@ export class NgForm extends ControlContainer implements Form {
     });
   }
 
-  onSubmit() {
+  onSubmit(): boolean {
     ObservableWrapper.callNext(this.ngSubmit, null);
     return false;
   }

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

@@ -124,7 +124,7 @@ export class NgFormModel extends ControlContainer implements Form {
     c.updateValue(value);
   }
 
-  onSubmit() {
+  onSubmit(): boolean {
     ObservableWrapper.callNext(this.ngSubmit, null);
     return false;
   }

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

@@ -9,7 +9,7 @@ import {Validators} from '../validators';
 import {Renderer, ElementRef, QueryList} from 'angular2/angular2';
 
 
-export function controlPath(name, parent: ControlContainer) {
+export function controlPath(name: string, parent: ControlContainer): string[] {
   var p = ListWrapper.clone(parent.path);
   p.push(name);
   return p;

modules/angular2/src/forms/model.ts

@@ -122,7 +122,7 @@ export class AbstractControl {
 
   find(path: List<string | number>| string): AbstractControl { return _find(this, path); }
 
-  getError(errorCode: string, path: List<string> = null) {
+  getError(errorCode: string, path: List<string> = null): any {
     var c = isPresent(path) && !ListWrapper.isEmpty(path) ? this.find(path) : this;
     if (isPresent(c) && isPresent(c._errors)) {
       return StringMapWrapper.get(c._errors, errorCode);
@@ -131,7 +131,7 @@ export class AbstractControl {
     }
   }
 
-  hasError(errorCode: string, path: List<string> = null) {
+  hasError(errorCode: string, path: List<string> = null): boolean {
     return isPresent(this.getError(errorCode, path));
   }