Make compatible for Windows and test on Windows

[benmaier]

Make compatible for Windows and test on Windows

[benmaier]

copying of JS-source files does not work. copying the data and config, however, does work.

also, there's this error:

KeyError                                  Traceback (most recent call last)
<ipython-input-1-8b5a672fdf69> in <module>
      5 
      6 G = nx.barabasi_albert_graph(1000,1)
----> 7 result, config = wulf.visualize(G)

c:\users\maierb\documents\python scripts\netwulf\netwulf-master\netwulf\interactive.py in visualize(network, port, verbose, config)
    282     # actually re-draw the figure and display it
    283     env = os.environ
--> 284     program = os.path.basename(env['_'])
    285     if 'jupyter' in program:
    286         fig, ax = wulf.draw_netwulf(posted_network_properties)

~\AppData\Local\Continuum\anaconda3\lib\os.py in __getitem__(self, key)
    676         except KeyError:
    677             # raise KeyError with the original key value
--> 678             raise KeyError(key) from None
    679         return self.decodevalue(value)
    680 

KeyError: '_'```

I guess, this is fixable by asking for key `'JPY_PARENT_PID'` in `os.environ`

[benmaier]

        # an empty POST means the server should be stopped
        if content_length == 0:
            try:
                body = self.rfile.read(content_length)
                self.send_response(200)
                self.end_headers()
                response = BytesIO()
                response.write(b'Closing now.')
                self.wfile.write(response.getvalue())
            except:
                self.server.end_requested = True
        else:

    # see whether or not the whole thing was started from a jupyter notebook and if yes,
    # actually re-draw the figure and display it
    env = os.environ
    try:
        is_jupyter = 'jupyter' in os.path.basename(env['_'])
    except:
        is_jupyter = 'JPY_PARENT_PID' in env 
    if is_jupyter:        
        fig, ax = wulf.draw_netwulf(posted_network_properties)