Translate import declarations into calls to require() in beforeInit.

[thomsbg]

Import hrefs are assumed to be relative to the current file, and so
the call to require has ./ prepended. e.g.

<link rel="ractive" href="test.ract" />
require('./test.ract');

If a beforeInit callback was specified in the component, it will be
called after the sub-components have been set into options. See the
new test case for an example.

Also, I refactored things slightly to branching on if (component.script). This causes var component = module to always be output, and the use of component.exports over just exports. Please let me know if that's a problem.

[marcello3d]

I'm not familiar with how beforeInit works, is it possible for options.components to already exist at this point?

[thomsbg]

Hmm, yes I think so, if you were to instantiate your component like so: new CustomComponent({ components: { ... } })

I'll revise to not overwrite any passed in options.

[thomsbg]

Ah, now I see #5. I didn't realize that component.exports.components would work, and so I think @MartinKolarik has a bit cleaner implementation. Let's concentrate our thoughts there.