Changing scenes does not automatically refresh the asset list

[davidkydd]

Currently, if the Batch plugin UI is left open and a new scene loaded, the Assets tab will not be auto-refreshed, and a job submitted from the new scene will render with assets and asset_map.mel from the previous scene.

[annatisch]

@davidkydd
This was originally supported for the assets and job submission settings.
To re-enable, you can uncomment these callbacks:
https://github.com/Azure/azure-batch-maya/blob/master/azure_batch_maya/scripts/assets.py#L66

Though it can introduce some instabilities and delays when loading a new scene - so you may want to test it out a bit.