This major refactoring of the catalog based shell utilizes the new API macro and
the API Schema as well as rustyline instead of the old GNU readline C API.
The code now has these 3 main components:
* The `Shell` which handles the readline loop via rustyline.
* The shell functions defined via the API macro.
* The `Context` which holds catalog and decoder instances.
Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
By changing the way shell commands are defined and parsed, this makes it more
straight forward to extend the current functionality.
The readline input is parsed based on the provided command definition and the
given parameters and options are passed to a command specific callback function.
In addition, the provided command definition including its description is used
to generate a help string to display.
The help command shows a list of all supported commands or the help string for
the provided command.
Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
And use an extra functzion set_callback() to configure that.
Also rewrite pxar/fuse.rs and implement a generic Session (will get
further cleanups with next patches).
