fixes to automatic updating and vae conversions

This PR makes the following minor fixes to the 2.3 branch:

1. The invokeai-update script will now recognize when the user
previously installed xformers and modifies the pip install command
so as to include xformers as an extra that needs to be updated.

2. In addition to looking for instances in which a user has entered a
VAE ckpt into the "vae" field directly, it also handles the case in
which the user entered a ckpt into the path field. These two cases
now work:

   vae: models/ldm/stable-diffusion-1/vae-ft-mse-840000-ema-pruned.ckpt

and

   vae:
      path: models/ldm/stable-diffusion-1/vae-ft-mse-840000-ema-pruned.ckpt

3. If a 32-bit checkpoint VAE is encountered and user is using half precision,
the VAE is now converted to 16 bits on the fly.

ldm/invoke/_version.py

@@ -1,2 +1,3 @@
-__version__='2.3.5.post1'
+__version__='2.3.5.post2'
+
 

ldm/invoke/config/invokeai_update.py

@@ -6,6 +6,7 @@ import os
 import platform
 import psutil
 import requests
+import pkg_resources
 from rich import box, print
 from rich.console import Console, group
 from rich.panel import Panel
@@ -72,6 +73,15 @@ def welcome(versions: dict):
     )
     console.line()
 
+def get_extras():
+    extras = ''
+    try:
+        dist = pkg_resources.get_distribution('xformers')
+        extras = '[xformers]'
+    except pkg_resources.DistributionNotFound:
+        pass
+    return extras
+
 def main():
     versions = get_versions()
     if invokeai_is_running():
@@ -94,13 +104,15 @@ def main():
     elif choice=='4':
         branch = Prompt.ask('Enter an InvokeAI branch name')
 
+    extras = get_extras()
+
     print(f':crossed_fingers: Upgrading to [yellow]{tag if tag else release}[/yellow]')
     if release:
-        cmd = f'pip install {INVOKE_AI_SRC}/{release}.zip --use-pep517 --upgrade'
+        cmd = f"pip install 'invokeai{extras} @ {INVOKE_AI_SRC}/{release}.zip' --use-pep517 --upgrade"
     elif tag:
-        cmd = f'pip install {INVOKE_AI_TAG}/{tag}.zip --use-pep517 --upgrade'
+        cmd = f"pip install 'invokeai{extras} @ {INVOKE_AI_TAG}/{tag}.zip' --use-pep517 --upgrade"
     else:
-        cmd = f'pip install {INVOKE_AI_BRANCH}/{branch}.zip --use-pep517 --upgrade'
+        cmd = f"pip install 'invokeai{extras} @ {INVOKE_AI_BRANCH}/{branch}.zip' --use-pep517 --upgrade"
     print('')
     print('')
     if os.system(cmd)==0:

ldm/invoke/model_manager.py

@@ -1229,12 +1229,16 @@ class ModelManager(object):
         return vae_path
                                
     def _load_vae(self, vae_config) -> AutoencoderKL:
-
+        using_fp16 = self.precision == "float16"
+        dtype = torch.float16 if using_fp16 else torch.float32
+        
         # Handle the common case of a user shoving a VAE .ckpt into
         # the vae field for a diffusers. We convert it into diffusers
         # format and use it.
-        if type(vae_config) in [str,Path]:
-            return self.convert_vae(vae_config)
+        if isinstance(vae_config,(str,Path)):
+            return self.convert_vae(vae_config).to(dtype=dtype)
+        elif isinstance(vae_config,DictConfig) and (vae_path := vae_config.get('path')):
+            return self.convert_vae(vae_path).to(dtype=dtype)
             
         vae_args = {}
         try:
@@ -1243,7 +1247,6 @@ class ModelManager(object):
             return None
         if name_or_path is None:
             return None
-        using_fp16 = self.precision == "float16"
 
         vae_args.update(
             cache_dir=global_cache_dir("hub"),
@@ -1285,7 +1288,7 @@ class ModelManager(object):
 
     @staticmethod
     def convert_vae(vae_path: Union[Path,str])->AutoencoderKL:
-        print(f"   | A checkpoint VAE was detected. Converting to diffusers format.")
+        print("   | A checkpoint VAE was detected. Converting to diffusers format.")
         vae_path = Path(Globals.root,vae_path).resolve()
         
         from .ckpt_to_diffuser import (