CLI improvements and missing features

[hoh]

This is a list of suggestions to add to the CLI:

• A user can subscribe to watch all messages, or messages from a specific address using aleph message watch
• A user can obtain the version number without extra text using aleph about version
• A user can list the instances she created
• A user can list the messages she published
• A user can list the programs she published
• A user can list the aggregates she published, as well as the individual update messages (via aleph message list ?)
• A user can list her compute/core nodes
• The command aleph node compute lists compute nodes. This does not seem intuitive versus aleph node list --compute for example.