qtconsoleapp 'parse_command_line' doen't like --existing anymore

[Carreau]

on master (87e2f91) Debian squeeze, with some wheezy and sid packages, X forwarding

launching a qtconsole,
python ipython.py qtconsole
and in another
python ipython.py qtconsole --existing kernel-9886.json

rise the following:

Traceback (most recent call last):
  File "ipython.py", line 21, in <module>
    this_dir, 'IPython', 'scripts', 'ipython'
  File "IPython/scripts/ipython", line 7, in <module>
    launch_new_instance()
  File "IPython/frontend/terminal/ipapp.py", line 390, in launch_new_instance
    app.initialize()
  File "IPython/frontend/terminal/ipapp.py", line 291, in initialize
    super(TerminalIPythonApp, self).initialize(argv)
  File "IPython/core/application.py", line 310, in initialize
    self.parse_command_line(argv)
  File "IPython/frontend/terminal/ipapp.py", line 287, in parse_command_line
    return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "IPython/config/application.py", line 388, in parse_command_line
    return self.initialize_subcommand(subc, subargv)
  File "IPython/config/application.py", line 332, in initialize_subcommand
    self.subapp.initialize(argv)
  File "IPython/frontend/qt/console/qtconsoleapp.py", line 558, in initialize
    super(IPythonQtConsoleApp, self).initialize(argv)
  File "IPython/core/application.py", line 310, in initialize
    self.parse_command_line(argv)
  File "IPython/frontend/qt/console/qtconsoleapp.py", line 351, in parse_command_line
    self.kernel_argv.remove(a)
ValueError: list.remove(x): x not in list

my guess is that at line 331 and 339 the two for a in argv: both match on a flag in argv (which is a copy of self.kernel_argv, line 331) and try to remove a from it twice... hence the crash.

I can fix it, but I'm not sure it will be the only place where this might append...

[minrk]

And I fixed this yesterday in the qtconsole_menu PR (cfc7e4a), but I suppose I should put that commit in master straight away, as it's a pretty big deal