support binding [form] data directly (#1996)

- ability to bind [form] data directly inside `<activiti-form>` component
- ability to parse forms with FormService
- demo of the custom form in demo shell

ng2-components/ng2-activiti-form/src/components/activiti-form.component.ts

@@ -40,6 +40,9 @@ export class ActivitiForm implements OnInit, AfterViewChecked, OnChanges {
     static START_PROCESS_OUTCOME_ID: string = '$startProcess';
     static CUSTOM_OUTCOME_ID: string = '$custom';
 
+    @Input()
+    form: FormModel;
+
     @Input()
     taskId: string;
 
@@ -103,8 +106,6 @@ export class ActivitiForm implements OnInit, AfterViewChecked, OnChanges {
     @Output()
     onError: EventEmitter<any> = new EventEmitter<any>();
 
-    form: FormModel;
-
     debugMode: boolean = false;
 
     constructor(protected formService: FormService,