fix(core/forms): input[type=text] .valueChanges fires unexpectedly

Closes #4768, #5284

Closes #5401

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

@@ -20,11 +20,7 @@ const DEFAULT_VALUE_ACCESSOR = CONST_EXPR(new Provider(
   // TODO: vsavkin replace the above selector with the one below it once
   // https://github.com/angular/angular/issues/3011 is implemented
   // selector: '[ng-control],[ng-model],[ng-form-control]',
-  host: {
-    '(change)': 'onChange($event.target.value)',
-    '(input)': 'onChange($event.target.value)',
-    '(blur)': 'onTouched()'
-  },
+  host: {'(input)': 'onChange($event.target.value)', '(blur)': 'onTouched()'},
   bindings: [DEFAULT_VALUE_ACCESSOR]
 })
 export class DefaultValueAccessor implements ControlValueAccessor {
@@ -40,4 +36,4 @@ export class DefaultValueAccessor implements ControlValueAccessor {
 
   registerOnChange(fn: (_: any) => void): void { this.onChange = fn; }
   registerOnTouched(fn: () => void): void { this.onTouched = fn; }
-}
+}