Merge branch '2.1' into 2.2

# Conflicts:
#	gns3server/compute/docker/docker_vm.py
#	gns3server/controller/compute.py
#	gns3server/controller/gns3vm/__init__.py
#	gns3server/controller/link.py
#	gns3server/controller/project.py
#	gns3server/handlers/api/controller/project_handler.py
#	gns3server/handlers/api/controller/server_handler.py
#	gns3server/utils/asyncio/__init__.py
#	gns3server/utils/asyncio/telnet_server.py
#	gns3server/version.py
#	gns3server/web/web_server.py
#	tests/compute/qemu/test_qemu_vm.py

gns3server/controller/gns3vm/__init__.py

@@ -21,7 +21,7 @@ import asyncio
 import aiohttp
 import ipaddress
 
-from ...utils.asyncio import locked_coroutine, asyncio_ensure_future
+from ...utils.asyncio import locking, asyncio_ensure_future
 from .vmware_gns3_vm import VMwareGNS3VM
 from .virtualbox_gns3_vm import VirtualBoxGNS3VM
 from .hyperv_gns3_vm import HyperVGNS3VM
@@ -278,13 +278,15 @@ class GNS3VM:
             except GNS3VMError as e:
                 # User will receive the error later when they will try to use the node
                 try:
-                    yield from self._controller.add_compute(compute_id="vm",
-                                                            name="GNS3 VM ({})".format(self.current_engine().vmname),
-                                                            host=None,
-                                                            force=True)
+                    compute = yield from self._controller.add_compute(compute_id="vm",
+                                                                      name="GNS3 VM ({})".format(self.current_engine().vmname),
+                                                                      host=None,
+                                                                      force=True)
+                    compute.set_last_error(str(e))
+
                 except aiohttp.web.HTTPConflict:
                     pass
-                log.error("Can't start the GNS3 VM: %s", str(e))
+                log.error("Cannot start the GNS3 VM: {}".format(e))
 
     @asyncio.coroutine
     def exit_vm(self):
@@ -298,7 +300,8 @@ class GNS3VM:
             except GNS3VMError as e:
                 log.warning(str(e))
 
-    @locked_coroutine
+    @locking
+    @asyncio.coroutine
     def start(self):
         """
         Start the GNS3 VM
@@ -323,8 +326,9 @@ class GNS3VM:
                 yield from engine.start()
             except Exception as e:
                 yield from self._controller.delete_compute("vm")
-                log.error("Can't start the GNS3 VM: {}".format(str(e)))
+                log.error("Cannot start the GNS3 VM: {}".format(str(e)))
                 yield from compute.update(name="GNS3 VM ({})".format(engine.vmname))
+                compute.set_last_error(str(e))
                 raise e
             yield from compute.connect()  # we can connect now that the VM has started
             yield from compute.update(name="GNS3 VM ({})".format(engine.vmname),
@@ -370,8 +374,11 @@ class GNS3VM:
                                 self._controller.notification.controller_emit("log.warning", {"message": msg})
         except ComputeError as e:
             log.warning("Could not check the VM is in the same subnet as the local server: {}".format(e))
+        except aiohttp.web.HTTPConflict as e:
+            log.warning("Could not check the VM is in the same subnet as the local server: {}".format(e.text))
 
-    @locked_coroutine
+    @locking
+    @asyncio.coroutine
     def _suspend(self):
         """
         Suspend the GNS3 VM
@@ -383,7 +390,8 @@ class GNS3VM:
             log.info("Suspend the GNS3 VM")
             yield from engine.suspend()
 
-    @locked_coroutine
+    @locking
+    @asyncio.coroutine
     def _stop(self):
         """
         Stop the GNS3 VM