core: import monitorlayoutnotify instead of calling it as external script

Otherwise deadlock could happen - the script will try to get read lock
on qubes.xml, while the calling tool can already hold the lock. If that
was write lock (which is in case of qfile-daemon-dvm), the deadlock
occurs.

core-modules/000QubesVm.py

@@ -1544,12 +1544,13 @@ class QubesVm(object):
         if (retcode != 0) :
             raise QubesException("Cannot start qubes-guid!")
 
-        if verbose:
-            print >> sys.stderr, "--> Sending monitor layout..."
-
         try:
-            subprocess.call([system_path["monitor_layout_notify_cmd"], self.name])
-        except Exception as e:
+            import qubes.monitorlayoutnotify
+            if verbose:
+                print >> sys.stderr, "--> Sending monitor layout..."
+            monitor_layout = qubes.monitorlayoutnotify.get_monitor_layout()
+            qubes.monitorlayoutnotify.notify_vm(self, monitor_layout)
+        except ImportError as e:
             print >>sys.stderr, "ERROR: %s" % e
 
         if verbose:

core/qubes.py

@@ -81,7 +81,6 @@ system_path = {
 
     'qubes_pciback_cmd': '/usr/lib/qubes/unbind-pci-device.sh',
     'prepare_volatile_img_cmd': '/usr/lib/qubes/prepare-volatile-img.sh',
-    'monitor_layout_notify_cmd': '/usr/bin/qubes-monitor-layout-notify',
 }
 
 vm_files = {