Xformers is now properly disabled when --cpu used.

Added --windows-standalone-build option, currently it only opens
makes the code open up comfyui in the browser.

server.py

@@ -260,7 +260,7 @@ class PromptServer():
             msg = await self.messages.get()
             await self.send(*msg)
 
-    async def start(self, address, port, verbose=True):
+    async def start(self, address, port, verbose=True, call_on_start=None):
         runner = web.AppRunner(self.app)
         await runner.setup()
         site = web.TCPSite(runner, address, port)
@@ -271,3 +271,6 @@ class PromptServer():
         if verbose:
             print("Starting server\n")
             print("To see the GUI go to: http://{}:{}".format(address, port))
+        if call_on_start is not None:
+            call_on_start(address, port)
+