Add tests

This commit adds tests to make sure that Harmony is present, compiled,
and variables are shared between files and versions of ECMAScript.
Resolve module.exports bug

The global `module.exports = function () { … }` doesn't allow variables to be
export to the global namespace.  This commit renames `module.exports` to
`harmony` if Traceur injects it.
Merge branch 'master' into fix-traceur-meteor-bugs
Use `this` to set global variables in test setup files
Merge pull request #16 from christianbundy/fix-traceur-meteor-bugs

Resolve strict mode and module.exports
Remove packages/.gitignore

I think that meteorite created this at some point, but it shouldn't have been committed.