[ALOY-449] Parsing state not clean when processing multiple top-level UI elements

Alloy is not properly using a fresh state when it is processing multiple top-level UI elements in view markup. For example, in the following case, an invalid state is passed to the final **actionBar** element, causing errors on Android.

<Alloy>
    <View id="dashboardContainer" platform="android"/>
    <TableView id="dashboard" platform="ios">
    	<TableViewSection/>
    </TableView>
    <View id="actionBar"/>
</Alloy>

The **actionBar** element will get assigned the wrong id, **dashboard**, during the parsing. In order to prevent this, Alloy needs to be sure to create a new, fresh state when processing each top-level UI element, not reuse the existing state from the prior top-level element.