made substantial enhancements to Browser

Browser class:
    ./lib/Browser.js

* supports HTTPS
* normalizes the output of parseUrl (for direct consumption by request)
* allows passing an optional jsdom features configuration object to the Browser constructor
* catches errors thrown by jsdom and rejects the promise
* prevents get(),post(), and postForm() from attempting to set a read-only property
* get():
    - better redirect handling,
    - url can be passed pre-parsed
* post():
    - url can be passed pre-parsed,
    - body content can be extracted from url querystring
    - corrected default content-type header
    - enabled sending content-length header (by default)
* postForm():
    - Form parameter is now optional;
      if not provided, it will be constructed from the request object
* [new method] submit_$form():
    - passed a jQuery match to a <form> DOM element
    - submits the <form> using an appropriate methodology
* pressButton():
    - updated. passes control to: submit_$form()

added a large number of unit tests:
    ./testing/tests/BrowserTest.js

additionally, minor tweak to Request:
    ./lib/Request.js