Making promises more compliant with standards.
Accepting loader plugins with no argument.

close #11
Changing the way the error module is called.

Instead of calling it with the error as the scope, it is now called with
the error as a parameter, which is more intuitive.
No longer reading the URL parameter if the config specifies a main module.
DOC: updating documentation related to 5e844cfe87050075e7f1ea36a09ea28652011100.
1.4.0