[TIMOB-20040] iOS: Missing NSParagraphStyle support

[NSParagraphStyle](https://developer.apple.com/library/ios/documentation/Cocoa/Reference/ApplicationKit/Classes/NSParagraphStyle_Class/index.html#//apple_ref/occ/cl/NSParagraphStyle) support is missing from the SDK. That means that there’s no way in a single Ti.UI.Label to define paragraphs and ‘block elements’ (a-la Web’s Box Model). This can be somehow worked around using multiple labels inside a View with layout=vertical, but this workaround is not applicable in ListView templates and ListDataItem protocol, where repeatable elements and/or dynamic views are not supported.