function unlinkToGlobal (cwd) {
	const pkg = require(path.join(cwd, 'package.json'))
	const symlinks = getSymlinks(cwd, pkg)
	return ArrayObservable.create(symlinks)
		::mergeMap(([src, dst]) => unlink(dst))
}
revert the effects of `ied link` by removing the previously created
symbolic links (used for `ied unlink`).
@param {String} cwd - current working directory.
@return {Observable} - observable sequence.