FIX: pageVar object in a @Repeat of an embedded "brick" is lost

This fix corrects the incorrect behavior when a "brick" (a class with `@EmbedAs` annotation) inside itself uses a `@Repeat` widget to iterate through some sort of collection: the MVEL compiler complains about non-existing properties of the `__page` (or some overridden symbol in the `pageVar` of the `@Repeat` widget) and throws an exception.

Attached acceptance tests that illustrate the issue.