[ALOY-1480] Bug/Regression: Data binding always returns string values

For ALOY-443 (Alloy 1.5.0) we started to use _.template() for complex model data binding. With ALOY-1368 and ALOY-1369 we also adopted this method for complex collection data binding. Since _.template() always returns a string, it doesn't work for binding objects, e.g. an attributedString as the attached test case:

<Alloy>
	<Collection src="source" />
	<Window class="container">
		<ListView id="List" defaultItemTemplate="test" top="30">
			<Templates>
				<ItemTemplate name="test" height="50">
					<View height="Ti.UI.SIZE" layout="vertical">
						<Label id="simpleTestLabel" bindId="simpleTestLabel"></Label>
						<Label id="attributedTestLabel" bindId="attributedTestLabel" top="5"></Label>
					</View>
				</ItemTemplate>
			</Templates>
			<ListSection dataCollection="source" dataTransform="transform">
				<ListItem simpleTestLabel:text="{simple}" attributedTestLabel:attributedString="{attributedString}"></ListItem>
			</ListSection>
		</ListView>
	</Window>
</Alloy>

Original description

Just tested that, using alloy v1.8.2 and v1.8.5 I was unable to set the attributedString property via a ListItem template. Using alloy 1.7.35 everything is working fine. I attach a simple test project that contains a ListView with a template composed by two labels. On the first label I set the text property with a simple model string and on the second one i set the attributedString. For the first label everything is working correctly (as expected) and for the second one is working only using v1.7.35 of alloy.