Support Import Statements - WIP

[Cmdv]

This is a part of #71

I'm not sure if it needed tests in Minify.hs + RoundTrip.hs also I'm wondering if this needs supports all the import specs

[erikd]

It would be best of this had tests.

There are also a couple of warnings in the Travis builds that really should be fixed.

[Cmdv]

yeah totally sorry it's a WIP to get some feedback.

just looking at the specs and I don't seem to cove everything but some of the cases I'm not too sure how to deal with:

import defaultExport from "module-name";
import * as name from "module-name";
import { export } from "module-name";
import { export as alias } from "module-name";
import { export1 , export2 } from "module-name";
import { export1 , export2 as alias2 , [...] } from "module-name";
import defaultExport, { export [ , [...] ] } from "module-name";
import defaultExport, * as name from "module-name";
import "module-name";
var promise = import(module-name);

the from and * I'd need pointers if that's ok?

[erikd]

I'd say get what you can working and passing tests and then the rest can be dealt with on an as needed basis.