Add failing test for "module foo from bar" syntax.
Always return a module object when using "module foo from bar".

Closes #66.
Use a multiline tagged string and unindent it properly.
Print a warning when importing a module exported as a function.
Use ES6 features where available.
Put module builder/safe warn code into reusable functions.

This way we'll generate less code in cases where there are two or more module imports.
Add a note about why the require call is where it is.
Merge pull request #74 from square/module-from

module foo from bar update