don't use os.kill on win32 platform

[Alexander Belchenko]

I've tried to Cancel qpull operation and get the traceback:

Traceback (most recent call last):
  File "C:\work\Bazaar\plugins\qbzr\lib\subprocess.py", line 157, in reject
    self.process_widget.abort()
  File "C:\work\Bazaar\plugins\qbzr\lib\subprocess.py", line 371, in abort
    os.kill(self.process.pid(), signal.SIGINT)
AttributeError: 'module' object has no attribute 'kill'
Connected (version 2.0, client Twisted)
Authentication (publickey) successful!
Secsh channel 1 opened.
Unable to obtain lock file:///C:/work/Bazaar/scmproj-repo/format-change/.bzr/branch/lock
held by <email address hidden> on host bialix-laptop [process #3352]
locked 2 minutes, 15 seconds ago
Will continue to try until 20:31:50, unless you press Ctrl-C
If you're sure that it's not being modified, use bzr break-lock file:///C:/work/Bazaar/scmproj-repo/format-change/.b
zr/branch/lock

os.kill is not available on Windows platform. Using it unconditionally is bad.

[Alexander Belchenko (bialix)]

Search for os.kill + win32 gave this:

* http://www.python.org/doc/faq/windows/#how-do-i-emulate-os-kill-in-windows
* http://buildbot.net/trac/ticket/77
* http://bugs.python.org/issue1220212

[Alexander Belchenko (bialix)]

Alexander Belchenko пишет:
> os.kill(self.process.pid(), signal.SIGINT)

BTW this code is wrong. At least on Windows.

self.process.pid() returns sip.voidptr object. If I cast it to int with the code
int(self.process.pid()) then I get pointer value, it's not the same as os.getpid()
result (I've checked via debug print in qsubprocess body).