use taskkill cmdline for jython/win32 but skip test on jython because it does not return a subprocess PID

--HG--
branch : trunk

py/_process/killproc.py

@@ -1,7 +1,7 @@
 import py
 import os, sys
 
-if sys.platform == "win32":
+if sys.platform == "win32" or getattr(os, '_name', '') == 'nt':
     try:
         import ctypes
     except ImportError:

testing/process/test_killproc.py

@@ -1,6 +1,7 @@
 
 import py, sys
 
+@py.test.mark.skipif("sys.platform.startswith('java')")
 def test_kill(tmpdir):
     subprocess = py.test.importorskip("subprocess")
     t = tmpdir.join("t.py")