Opener test: check for the existence of each file.

Test goes through each dependency (using opener.each) and fetches the text from the file. If it doesn't throw, the test will pass. Related: #138
Added test to check for rootSteal vs steal

Added a test to the opener that makes sure the `rootSteal` is the steal opened on the page, and not the `steal` that exists in Node. Related #138
Merge branch 'node' into js-async