Fixing numerous bugs in ipcluster on Win32.

* External processes are now started by calling "python.exe -u"
* We find external process locations by importing them and using their
  __file__ attribute.  This make the search robust against different
  ways of installing the scripts on Win32.
* We now check to make sure that if the user wants to run in secure mode
  that pyOpenSSL is actually installed and working.  This is now done in
  the controller, engine and ipcluster.

IPython/kernel/scripts/ipcluster.py

@@ -31,6 +31,8 b' from IPython.external import Itpl'
 from IPython.kernel.twistedutil import gatherBoth
 from IPython.kernel.util import printer
 from IPython.genutils import get_ipython_dir, num_cpus
+from IPython.kernel.fcutil import have_crypto
+from IPython.kernel.error import SecurityError
 
 #-----------------------------------------------------------------------------
 # General process handling code
@@ -174,7 +176,13 b' class ControllerLauncher(ProcessLauncher):'
     
     def __init__(self, extra_args=None):
         if sys.platform == 'win32':
-            args = [find_exe('ipcontroller')]
+            # This logic is needed because the ipcontroller script doesn't
+            # always get installed in the same way or in the same location.
+            from IPython.kernel.scripts import ipcontroller
+            script_location = ipcontroller.__file__.replace('.pyc', '.py')
+            # The -u option here turns on unbuffered output, which is required
+            # on Win32 to prevent wierd conflict and problems with Twisted
+            args = [find_exe('python'), '-u', script_location]
         else:
             args = ['ipcontroller']
         self.extra_args = extra_args
@@ -188,7 +196,13 b' class EngineLauncher(ProcessLauncher):'
     
     def __init__(self, extra_args=None):
         if sys.platform == 'win32':
-            args = [find_exe('ipengine')]
+            # This logic is needed because the ipcontroller script doesn't
+            # always get installed in the same way or in the same location.
+            from IPython.kernel.scripts import ipengine
+            script_location = ipengine.__file__.replace('.pyc', '.py')
+            # The -u option here turns on unbuffered output, which is required
+            # on Win32 to prevent wierd conflict and problems with Twisted
+            args = [find_exe('python'), '-u', script_location]
         else:
             args = ['ipengine']
         self.extra_args = extra_args
@@ -314,13 +328,27 b' class PBSEngineSet(BatchEngineSet):'
 # The main functions should then just parse the command line arguments, create
 # the appropriate class and call a 'start' method.
 
-def main_local(args):
-    cont_args = []
-    cont_args.append('--logfile=%s' % pjoin(args.logdir,'ipcontroller'))
+def check_security(args, cont_args):
+    if (not args.x or not args.y) and not have_crypto:
+        log.err("""
+OpenSSL/pyOpenSSL is not available, so we can't run in secure mode.
+Try running ipcluster with the -xy flags:  ipcluster local -xy -n 4""")
+        reactor.stop()
+        return False
     if args.x:
         cont_args.append('-x')
     if args.y:
         cont_args.append('-y')
+    return True
+
+def main_local(args):
+    cont_args = []
+    cont_args.append('--logfile=%s' % pjoin(args.logdir,'ipcontroller'))
+
+    # Check security settings before proceeding
+    keep_going = check_security(args, cont_args)
+    if not keep_going: return
+
     cl = ControllerLauncher(extra_args=cont_args)
     dstart = cl.start()
     def start_engines(cont_pid):
@@ -349,10 +377,11 b' def main_local(args):'
 def main_mpirun(args):
     cont_args = []
     cont_args.append('--logfile=%s' % pjoin(args.logdir,'ipcontroller'))
-    if args.x:
-        cont_args.append('-x')
-    if args.y:
-        cont_args.append('-y')
+
+    # Check security settings before proceeding
+    keep_going = check_security(args, cont_args)
+    if not keep_going: return
+
     cl = ControllerLauncher(extra_args=cont_args)
     dstart = cl.start()
     def start_engines(cont_pid):
@@ -385,10 +414,11 b' def main_mpirun(args):'
 def main_pbs(args):
     cont_args = []
     cont_args.append('--logfile=%s' % pjoin(args.logdir,'ipcontroller'))
-    if args.x:
-	cont_args.append('-x')
-    if args.y:
-	cont_args.append('-y')
+
+    # Check security settings before proceeding
+    keep_going = check_security(args, cont_args)
+    if not keep_going: return
+
     cl = ControllerLauncher(extra_args=cont_args)
     dstart = cl.start()
     def start_engines(r):