Issue #1: Changing library to be fluent plus simplified API
Issue #1: Changing library to be fluent plus simplified API

This commit simplifies the library to be more fluent as described on
issue #1. This makes it simpler to be used.

*	modified:   lib/middleware.js
- Removing the events and utils, as it does NOT issue any.
- Returning an instance of the middleware with default values
- Default values only has fromDir being the current PWD.
- APP_DIR is now a property of the class.
- Adding the method from(), which sets the fromDir and keep it fluent by
  returning the this reference.
- Renaming the method load() to require() to ressamble node.js
- Simplifying the error message, with full path to the module as the
  default error. However, renaming "module" to "middleware" in the error
  message.

marcellodesales/middleware-js