Wrap up SyntaxHighlighter as a NativeScript component

[shirakaba]

This would require implementing at least a stub for Android, as we don't yet have Android support: #2.

I tried creating this as a component, both:

• using XML (largely undocumented), and
• fully programmatically.

However, I couldn't get either working. One of these methods broke hot-reloading (I think the programmatic one), while the other simply wouldn't be imported by the bundler (and thus didn't get transpiled to JS) or didn't trigger expected lifecycle methods (and thus wouldn't begin to construct itself). Someone more familiar with NativeScript's intricacies may have better luck here.

I think it would be awesome to have it as an XML-specifiable component if possible, but I think I made more progress on the programmatic one in practice.

Difficulties: getting the initial bounds of the UITextView may require it to know the dimensions of its native parent in some way. I don't really know.

[shirakaba]

Closed by #8.