Error starting php debug

script:

``` php
", line 1, in
File "/usr/local/lib/python2.7/dist-packages/vim_debug/commands.py", line 19, in debugger_cmd
return start(*shlex.split(plain))
File "/usr/local/lib/python2.7/dist-packages/vim_debug/commands.py", line 92, in start
debugger.start_url(url)
File "/usr/local/lib/python2.7/dist-packages/vim_debug/new_debugger.py", line 103, in start_url
return self.start()
File "/usr/local/lib/python2.7/dist-packages/vim_debug/new_debugger.py", line 130, in start
if not self.bend.connect():
File "/usr/local/lib/python2.7/dist-packages/vim_debug/dbgp.py", line 86, in accept
serv.bind(('', self.options.get('port', 9001)))
File "/usr/lib/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
socket.error: [Errno 98] Address already in use
```

I have xdebug configured to run on port 9001, so I changed dbg.py to use that port. (I don't know if there is a vim configuration variable to change this, but I don't think that this is the problem. I'm running vim 7.4.

Start by reproducing the :Dbg http://localhost/phpinfo.php command with the reported PHP and Xdebug setup, then read vim_debug/commands.py and vim_debug/dbgp.py around the debugger start and socket bind calls. Done means the reported address-in-use failure is understood and the debugger can start with the configured port, with any relevant configuration behavior documented.

Written by the indexing model from the issue text.