Unlike consoles, where the underlying concept is a real
persistent thing that needs some care to reattach to watch,
a shell session should die when it is lost, as a new one would
have to be created anyway. Modify the disconnect behavior
for a shell session to set closed and notify the receivers.
It should also reap dependent watching objects in a future
change.
This causes some additional features into core. Namely
the ability to use a fixed module rather than a string
defined plugin. This allows shellserver to implement the
'plugin' interface without living in 'plugins'. 'plugins'
implies modularity and potential eventual choice, but
this functionality is core. It would make sense for the
'attributes' plugin to be changed to match this strategy.
UUIDs when a simple number will do are harder to use.
Change to a simple increment id. This could cause an issue
with multiple management nodes, but I think the sessions
should be contained to the instance used.
console logging assumptions are not valid for shell sessions.
Correct by modifying the buffer init code to be conditional
and adding a stub 'log' to the ShellHandler class.
Provide a common 'shellserver' capability cloned off of 'consoleserver'.
This will enable the concept of per-user shells with option for multiple
shells per. Each user will have their own set of shell sessions rather
than shared across users. Can revisit in future if sharing between
users is desired.
