v0.32.0

This release makes use of more features from prompt_toolkit. In particular, command history is now handled by prompt_toolkit (instead of readline). This means that the format of history files has changed, and that means that this is a major release. The upgrade is handled automatically, however, old history of existing workspaces will be deleted. (I don't think there is enough marcel usage for this to upset anyone. I am certainly the major, and perhaps only user, and even I don't mind.)

Marcel now has no dependencies on the readline module. Let the porting begin.